Indeno-fused photochromic naphthopyrans

ABSTRACT

Described are novel photochromic indeno-fused naphthopyran compounds, examples of which include naphthopyran compounds having a substituted or unsubstituted indeno group, the 2,1 positions of which are fused to the naphtho portion of the naphthopyran as shown below. Also present on the naphthopyran are moderate to strong electron donor substituents at the number 6- and 7-positions and optionally at the 8-position of the pyran ring or a cyclic group fused to the h side of the naphtho portion and weak to moderate electron donor substiuents at the 3-position of the pyran ring. Certain substituents may also be present at the number 5, 8, 9, 10, 11, 12, or 13 carbon atoms of the compounds. These compounds have a rating of at least 80 in the Relative ΔOD at Saturation Test and may be represented by the following graphic formula:                    
     Also described are polymeric organic host materials that contain or that are coated with such compounds. Optically clear articles such as ophthalmic lenses or other plastic transparencies that incorporate the novel naphthopyran compounds or combinations thereof with complementary photochromic compounds, e.g., certain other naphthopyrans, benzopyrans, and spiro(indoline)type compounds, are also described.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. provisional applicationSerial No. 60/154,428, filed Sep. 17, 1999 and U.S. provisionalapplication Serial No. 60/164,653, filed Nov. 10, 1999.

DESCRIPTION OF THE INVENTION

The present invention relates to certain novel naphthopyran compounds.More particularly, this invention relates to novel indeno-fusedphotochromic naphthopyran compounds and to compositions and articlescontaining such novel naphthopyran compounds. When exposed to lightradiation containing ultraviolet rays, such as the ultraviolet radiationin sunlight or the light of a mercury lamp, many photochromic compoundsexhibit a reversible change in color. When the ultraviolet radiation isdiscontinued, such a photochromic compound will return to its originalcolor or colorless state.

Various classes of photochromic compounds have been synthesized andsuggested for use in applications in which a sunlight-induced reversiblecolor change or darkening is desired. U.S. Pat. No. 3,567,605 (Becker)describes a series of pyran derivatives, including certain benzopyransand naphthopyrans. These compounds are described as derivatives ofchromene and are reported to undergo a color change, e.g., fromcolorless to yellow-orange, on irradiation by ultraviolet light attemperatures below about −30° C. Irradiation of the compounds withvisible light or upon raising the temperature to above about 0° C. isreported to reverse the coloration to a colorless state.

U.S. Pat. No. 5,066,818 describes various3,3-diaryl-3H-naphtho[2,1-b]pyrans as having desirable photochromicproperties, i.e., high colorability and acceptable fade, for ophthalmicand other applications. Also disclosed by way of comparative example inthe '818 patent are the isomeric 2,2-diaryl-2H-naphtho[1,2-b]pyrans,which are reported to require unacceptably long periods of time to fadeafter activation.

U.S. Pat. No. 3,627,690 describes photochromic2,2-di-substituted-2H-naphtho[1,2-b]pyran compositions containing minoramounts of either a base or weak-to-moderate strength acid. The additionof either an acid or base to the naphthopyran composition is reported toincrease the fade rate of the colored naphthopyrans, thereby making themuseful in eye protection applications such as sunglasses. It is reportedtherein further that the fade rate of 2H-naphtho-[1,2-b]pyrans withoutthe aforementioned additives ranges from several hours to many days toreach complete reversion.

While the activated form of a typical organic photochromic moleculeabsorbs in the visible region over a relatively narrow range (Van Gemertand Kish, PPG Technology Journal, Vol. 5, pg. 53-61, 1999), broaderabsorbing naphthopyrans (i.e. those having two absorption bands), arenot unknown. U.S. Pat. No. 5,645,767 discloses photochromicindeno[2,1-f]naphtho[1,2-b]pyrans having a blue/gray activated color. Ablue/gray color will be perceived when there is a major absorption ofvisible light in the 580-620 nm range coupled with a minor absorption inthe 420-500 nm range.

International Patent Application Publication No. WO 99/15518 disclosesphotochromic indeno[2,1-f]naphtho[1,2-b]pyrans having a green activatedcolor. A green color will be perceived when there is a major absorptionof visible light in the 580-620 nm range coupled with a major absorptionof roughly equal intensity in the 400-480 nm range.

While it is obvious from the previous description that it is possible toobtain many complex activated colors, it is not disclosed in theaforementioned patent or application how to select substituents for boththe pyrano and the indeno-fused naphtho portions of theindeno[2,1-f]naphtho[1,2-b]pyran in order to control the wavelengthand/or intensity of the absorbance bands within the activated visiblespectra.

The present invention discloses what types of substituents and wherethey may be placed in order to control the wavelength and/or intensityof the visible absorbance bands of indeno[2,1-f]naphtho[1,2-b]pyranshaving 2 intense spectral bands in the visible spectrum.

These novel naphthopyrans are substituted with weak to moderate electrondonor groups at the 3-position of the pyran ring and have eithermoderate to strong electron donor groups at the 6- and 7-position or acyclic group fused to the h face. The compounds may optionally have atthe 8-position moderate to strong electron donor groups and may haveother substituents at the 5-, 8-, 9-, 10-, 11-, 12- or 13-positions ofthe compound. The selection and placement of these substituents being sothat that the photochromic compounds of the present invention have arating of at least 80 in the Relative ΔOD at Saturation Test, describedhereinafter.

Generally, the activated (colored) form of these photochromic compoundshave an optical density of band “A” which is of greater intensity thanthe optical density of band “B”. The absorption of band “A” occurs inthe 420-500 nm region while the absorption of band “B” occurs in the500-650 nm region of the activated visible spectrum. These compoundsexhibit an apparent blended gray, brown or green activated color. Theuse of certain individual compounds of the present inventionsubstantially eliminates the need for combining two or more compounds toobtain neutral colors such as gray or brown. In addition, thesecompounds have demonstrated a high molar absorptivity (or molarextinction coefficient) in the ultraviolet (UV) light range, anacceptable fade rate without the addition of acids or bases, a highactivated intensity and a high coloration rate.

DETAILED DESCRIPTION OF THE INVENTION

In recent years, photochromic plastic materials, particularly plasticmaterials for optical applications, have been the subject ofconsiderable attention. In particular, photochromic ophthalmic plasticlenses have been investigated because of the weight advantage theyoffer, vis-a-vis, glass lenses. Moreover, photochromic transparenciesfor vehicles, such as cars and airplanes, have been of interest becauseof the potential safety features that such transparencies offer.

In accordance with the present invention, it has now been discoveredthat certain novel indeno[2,1-f]naphtho[1,2-b]pyrans having twoabsorption bands in the activated (colored) state, an acceptable faderate, high activated intensity, a high coloration rate and a rating of80 or higher in the Relative ΔOD at Saturation Test may be prepared. TheRelative ΔOD at Saturation Test is described in Example 21. The ratingsof the test are defined herein as the result obtained when the opticaldensity of band “A” is divided by the optical density of band “B” andmultiplied by 100. It is believed that compounds having a rating of 80or higher are most valuable for formulating neutral grays, greens andbrowns for commercial photochromic ophthalmic eyeware.

The naphthopyrans of the present invention may have a rating in theRelative ΔOD at Saturation Test of at least 80, preferably at least 90,more preferably from 90 to 150 and most preferably, from 100 to 130. Therating is expected to be less than 500, preferably less than 400, morepreferably less than 300 and most preferably less than 200. The ratingfor the naphthopyrans may range between any combination of these values,inclusive of the recited values, e.g., from at least 80 to less than500. The naphthopyrans of the present invention may have a ratinggreater than 500 if the two absorption bands are distinguishable and anoptical density is obtainable for the calculation.

Preparation of such compounds is achieved by balancing the effects ofthe potential substituents as described hereinafter. For example, the“A” band of these compounds can be enhanced relative to the “B” band byemploying strong electron donor substituents in the 7-position, moderateelectron donors in the 6-position, and weak to moderate electron donorsin the 3-position of the pyran ring. Compounds having relativelyequivalent intensity for the “A” and “B” bands can be obtained by havingelectron donors of relatively equal intensity at the 6- and 7-positionsand weak to moderate electron donors at the 3-position of the pyranring. Strong electron donors on an aryl grouping at the 3-position ofthe pyran will enhance the “B” band relative to the “A” band. Theintensity or strength of the electron donors at the 3-position of thepyran ring will not only effect the relative intensity of the twospectral bands, but also their position. For example, strong electrondonors on an aryl grouping at the 3-position will shift both bandsbathochromically (the “B” band more than the “A” band).

The relative strength of electron donor groups is frequently describedby Hammett Sigma values (specifically σ_(p) values). A tabular listingof σ_(p) constants for a variety of substituents can be found in“Exploring QSAR, Hydrophobic, Electronic, and Steric Constants, C.Hansch, A. Leo, and D. Hoekman, Eds., Published by The American ChemicalSociety, Washington, D.C., 1995, which disclosure is incorporated hereinby reference. Examples of strong electron donors, defined herein ashaving a Hammett σ_(p) value of between −1.0 and −0.5, that may be usedat the 6- and 7-positions or at the para position of an aryl groupingpresent at the 3-position of the pyrano portion of the naphthopyraninclude amino, monoalkylamino, dialkylamino, morpholino, and piperidino.Examples of moderate electron donors, defined herein as having aσ_(p)value of between −0.49 and −0.20 that may be used at the 6- and7-positions or at the para position of an aryl grouping present at the3-position of the pyrano portion of the naphthopyran include ethoxy,methoxy, and p-aminophenyl. Examples of weak electron donors, definedherein as having a Hammett σ_(p) value of between −0.01 and −0.19 thatmay be used at the 3-position of the pyrano portion of the naphthopyraninclude methyl, ethyl, phenyl, naphthyl, and tolyl.

The compounds may be described as naphthopyrans ofindeno[2,1-f]naphtho[1,2-b]pyran structure which are characterized byhaving moderate to strong electron donor groups R₅, and R₆, at the 7 and6 positions, respectively, or a cyclic group fused to the h face,moderate to strong electron donors optionally, at the 8 position, weakto moderate electron donor substituents at the 3-position and a ratingof at least 80 in the Relative ΔOD at Saturation Test. These compoundsmay have certain other substituents at the number 5, 8, 9, 10, 11, 12,or 13 carbon atoms of the indeno-fused portion of the compound.

The compounds of the present invention may be represented by thefollowing graphic formula I in which the letters a through u on theoutside of the ring structure represent the faces or sides of theindeno-fused naphthopyran ring, and the numbers on the inside of thering structure represent the positions of the ring atoms of thenaphthopyran:

In graphic formula I, R₁ and R₂ may each be selected from the groupconsisting of:

(i) hydrogen, hydroxy, C₁-C₆ alkyl, amino, mono- or di-substitutedamino, C₃-C₇ cycloalkyl, allyl, benzyl, mono-substituted benzyl, chloro,fluoro, the group —C(O)W, wherein W is hydroxy, C₁-C₆ alkyl, C₁-C₆alkoxy, phenyl, mono-substituted phenyl, amino, mono(C₁-C₆)alkylamino ordi(C₁-C₆)alkylamino, e.g. N,N-dimethyl amino, N-methyl-N-propyl amino,etc., morpholino, piperidino or pyrrolidyl, said amino substituentsbeing selected from the group consisting of C₁-C₆ alkyl, phenyl, benzyland naphthyl, and said benzyl and phenyl substituents being C₁-C₆ alkylor C₁-C₆ alkoxy;

(ii) the unsubstituted, mono- di-or trisubstituted groups phenyl,naphthyl, phenanthryl, pyrenyl, quinolyl, isoquinolyl, benzofuranyl,thienyl, benzothienyl, dibenzofuranyl, dibenzothienyl, carbazolyl,indolyl, said group substituents in this section (ii) being selectedfrom the group consisting of chloro, fluoro, C₁-C₆ alkyl and C₁-C₆alkoxy;

(iii) monosubstituted phenyl having a substituent at the para positionthat is a linking group, —(CH₂)_(t)— or —O—(CH₂)_(t)—, wherein t is theinteger 1, 2, 3, 4, 5 or 6, connected to an aryl group, e.g. phenyl ornaphthyl, which is a member of another photochromic naphthopyran, suchas naphtho[2,1-b]pyran or naphtho[1,2-b]pyran;

(iv) the group, —OR₈, wherein R₈ is C₁-C₆ alkyl, C₁-C₆ acyl,phenyl(C₁-C₃)alkyl, mono(C₁-C₆)alkyl substituted phenyl(C₁-C₃)alkyl,mono(C₁-C₆)alkoxy substituted phenyl(C₁-C₃)alkyl, C₁-C₆alkoxy(C₂-C₄)alkyl, C₃-C₇ cycloalkyl, mono(C₁-C₄)alkyl substituted C₃-C₇cycloalkyl, C₁-C₆ chloroalkyl, C₁-C₆ fluoroalkyl, allyl, benzoyl,monosubstituted benzoyl, naphthoyl or monosubstituted naphthoyl, saidbenzoyl and naphthoyl group substituents being C₁-C₆ alkyl or C₁-C₆alkoxy, or R₈ is the group, —CH(R₉)Q, wherein R₉ is hydrogen or C₁-C₃alkyl and Q is —CN, —CF₃, or —COOR₁₀, wherein R₁₀ is hydrogen or C₁-C₃alkyl, or R₈ is the group, —C(O)V, wherein V is hydrogen, C₁-C₆ alkoxy,phenoxy, mono- or di-(C₁-C₆)alkyl substituted phenoxy, mono- ordi-(C₁-C₆)alkoxy substituted phenoxy, the unsubstituted, mono- ordi-substituted aryl groups, phenyl and naphthyl, amino,mono(C₁-C₆)alkylamino, di(C₁-C₆)alkylamino, phenylamino, mono- ordi-(C₁-C₆)alkyl substituted phenylamino, or mono- or di-(C₁-C₆)alkoxysubstituted phenylamino, said aryl group substituents being C₁-C₆ alkylor C₁-C₆ alkoxy;

(v) the group —CH(Q′)2 wherein Q′ is —CN or —COOR₁₁, wherein R₁₁ ishydrogen, C₁-C₆ alkyl, phenyl(C₁-C₃)alkyl, mono(C₁-C₆)alkyl substitutedphenyl(C₁-C₃)alkyl, mono(C₁-C₆)alkoxy substituted phenyl(C₁-C₃)alkyl, orthe unsubstituted, mono- or di-substituted aryl groups phenyl ornaphthyl, said aryl group substituents being C₁-C₆ alkyl or C₁-C₆alkoxy;

(vi) the group —CH(R₁₂)G, wherein R₁₂ is hydrogen, C₁-C₆ alkyl or theunsubstituted, mono- or di-substituted aryl groups phenyl and naphthyl,and G is —COOR₁₁, —C(O)R₁₃ or —CH₂OR₁₄, wherein R₁₃ is hydrogen, C₁-C₆alkyl, the unsubstituted, mono- or di-substituted aryl groups phenyl ornaphthyl, amino, mono(C₁-C₆)alkylamino, di(C₁-C₆)alkylamino, e.g.,dimethyl amino, methyl propyl amino, etc., phenylamino, mono- ordi-(C₁-C₆)alkyl substituted phenylamino, mono- or di(C₁-C₆)alkoxysubstituted phenylamino, diphenylamino, mono- or di(C₁-C₆)alkylsubstituted diphenylamino, i.e., each phenyl has one or two C₁-C₆ alkylsubstituents, mono- or di(C₁-C₆)alkoxy substituted diphenylamino, i.e.,each phenyl has one or two C₁-C₆ alkoxy substituents, morpholino, orpiperidino, wherein R₁₄ is hydrogen, —C(O)R₁₁, C₁-C₆ alkyl, C₁-C₃alkoxy(C₁-C₆)alkyl, phenyl(C₁-C₃)alkyl, mono(C₁-C₆)alkoxy substitutedphenyl(C₁-C₃)alkyl, or the unsubstituted, mono- or di-substituted arylgroups phenyl or naphthyl, each of said aryl group substituents beingC₁-C₆ alkyl or C₁-C₆ alkoxy; and

(vii) the polyalkoxylated group T represented by the formula:

—Z[(OC₂H₄)_(x)(OC₃H₆)_(y) (OC₄H₈)_(z)]Z′ or

—[(OC₂H₄)_(x) (OC₃H₆)_(y) (OC₄H₈)_(z]Z′)

wherein —Z is —C(O)- or —CH2— and Z′ is C₁-C₃ alkoxy or a polymerizablegroup i.e., any functional group capable of participating in apolymerization reaction. Polymer forming methods in which thepolymerizable compounds of the present invention may participate includeradical polymerization, and such other polymerization processes as aredescribed in Ullmann's Encyclopedia of Industrial Chemistry,“Polymerization Processes”, Vol. 21A, pp 305 to 428, which disclosure isincorporated herein by reference. The polymerizable groups may beselected from the group consisting of hydroxy, (meth)acryloxy, andepoxy, e.g., oxiranylmethyl. When there are 2 or more polymerizablegroups on the naphthopyran, they may be the same or different.

The group, —(OC₂H₄)_(x)—, represents poly(ethylene oxide);—(OC₃H₆)_(y)—, represents poly(propylene oxide); and, —(OC₄H₈)_(z)—,represents poly(butylene oxide). When used in combination, thepoly(ethylene oxide), poly(propylene oxide) and poly(butylene oxide)groups of T may be in a random or block order within the T moiety. Theletters x, y and z are each a number between 0 and 50 and the sum of x,y and z is between 2 and 50. The sum of x, y and z may be any numberthat falls within the range of 2 to 50, e.g., 2, 3, 4 . . . 50. This summay also range from any lower number to any higher number within therange of 2 to 50, e.g., 6 to 50, 31 to 50. The numbers for x, y, and zare average values and can be partial numbers, e.g., 9.5.

Alternatively, R₁ and R₂ may together form an oxo group, aspiro-carbocyclic ring containing 3 to 6 carbon atoms or aspiro-heterocyclic group containing 1 or 2 oxygen atoms and 3 to 6carbon atoms including the spirocarbon atom and both rings may bebenz-annelated with one or two benzene groups. The spiro-carbocyclicring and spiro-heterocyclic group may also be substituted with one ortwo substituents selected from hydrogen or C₁-C₆ alkyl. Examples of thespiro-carbocyclic ring substituents include spirofluoreno,spirocyclopropyl, spirocyclobutyl, spirocyclopentyl, spirocyclohexyl,spiroindan-1-yl, spiroindan-2-yl, etc. Examples of thespiro-heterocyclic group include spiroxantheno and compounds which maybe represented by the expression (-0-(C₂-C₅ alkanediyl)-0-), e.g.,spiro-1,3-dioxolane-2, spiro-1,3-dioxane-2, etc. or spirolactones suchas butyrolactone, propiolactone etc. In the definitions of R₁ and R₂,like substituents have like meanings.

Preferably, R₁ and R₂ are each selected from the group consisting ofhydrogen, hydroxy, C₁-C₄ alkyl, C₃-C₆ cycloalkyl, chloro, fluoro and thegroup, —OR₈, wherein R₈ is C₁-C₃ alkyl, phenyl(C₁-C₂)alkyl,mono(C₁-C₃)alkyl substituted phenyl(C₁-C₃)alkyl, mono(C₁-C₃)alkoxysubstituted phenyl(C₁-C₃)alkyl, C₁-C₃ alkoxy(C₂-C₄)alkyl, C₁-C₃chloroalkyl, C₁-C₃ fluoroalkyl, the group, —CH(R₉)Q, wherein R₉ ishydrogen or C₁-C₂ alkyl and Q is —CN or —COOR₁₀, R₁₀ being hydrogen orC₁-C₂ alkyl, or R₈ is the group, —C(O)V, wherein V is hydrogen, C₁-C₃alkoxy, phenyl, naphthyl, the mono-substituted aryl groups, phenyl ornaphthyl, phenoxy, mono- or di-(C₁-C₃)alkyl substituted phenoxy, mono-or di-(C₁-C₃)alkoxy substituted phenoxy, mono(C₁-C₃)alkylamino,phenylamino, mono- or di-(C₁-C₃)alkyl substituted phenylamino, or mono-or di-(C₁-C₃)alkoxy substituted phenylamino, each of said aryl groupsubstituents being C₁-C₃ alkyl or C₁-C₃ alkoxy, or R₁ and R₂ are eachthe group T wherein x and y are each a number between 0 and 50, z is 0and the sum of x and y is between 2 and 50, and more preferably, x is anumber between 2 and 50, and y and z are each 0. More preferably, R₁ andR₂ are each hydrogen, hydroxy, C₁-C₃ alkyl or the group, —OR₈, whereinR₈ is C₁-C₃ alkyl.

Each R₃ in graphic formula I may be group T, C₁-C₆ alkyl, C₁-C₆ alkoxy,C₃-C₇ cycloalkyl, phenyl, benzyl, di(C₁-C₆)alkylamino,dicyclohexylamino, diphenylamino, piperidyl, morpholinyl, pyridyl,bromo, chloro, fluoro, or the group —C(O)W, and n is the integer 0, 1,or 2, or when n is 2 and the R₃ groups are adjacent, the R₃ groups maytogether form a fused carbocyclic or a fused heterocyclic ring selectedfrom the group consisting of benzo, pyridino, pyrazino, pyrimidino,furano, dihydrofurano and thiopheno, said ring being fused to the n, oor p sides of the indeno-fused naphthopyran. Preferably, R₃ is C₁-C₆alkyl, C₁-C₆ alkoxy, chloro or fluoro, and n is the integer 0, 1, or 2.More preferably, R₃ is C₁-C₃ alkoxy and n is the integer 0, 1 or 2.

In graphic formula I, the substituents R₅, R₆ and optionally R₄ aremoderate to strong electron donating groups defined herein. When R₄ isnot a moderate to strong electron donating group, it may be selectedfrom the same group of substituents as R₇, specifically hydrogen, C₁-C₆alkyl, chloro, or fluoro. Preferably, R₄ and R₇ are each selected fromhydrogen, C₁-C₃ alkyl, chloro or fluoro, and more preferably hydrogen.The moderate to strong electron donating groups of R₅ and R₆ andoptionally R₄, may be selected from:

(i) the group, —OR₈′, wherein R₈ ¹ is phenyl(C₁-C₃)alkyl, C₁-C₆ alkyl,mono(C₁-C₆)alkyl substituted phenyl(C₁-C₃)alkyl, mono(C₁-C₆)alkoxysubstituted phenyl(C₁-C₃)alkyl, C₁-C₆ alkoxy(C₂-C₄)alkyl, C₃-C₇cycloalkyl, mono(C₁-C₄)alkyl substituted C₃-C₇ cycloalkyl, C₁-C₆chloroalkyl, C₁-C₆ fluoroalkyl, allyl, or R₈′ is the group, —CH(R₉)Q,wherein R₉ is hydrogen or C₁-C₃ alkyl and Q is as defined before; and

(ii) a group selected from:

(1) —N(R₁₅)R₁₆, wherein R₁₅ and R₁₆ are each selected from the groupconsisting of hydrogen, C₁-C₈ alkyl, phenyl, naphthyl, theheteroaromatic groups furanyl, benzofuran-2-yl, benzofuran-3-yl,thienyl, benzothien-2-yl, benzothien-3-yl, dibenzofuranyl,dibenzothienyl, benzopyridyl and fluorenyl, C₁-C₈ alkylaryl, C₃-C₂₀cycloalkyl, C₄-C₂₀ bicycloalkyl, C₅-C₂₀ tricycloalkyl and C₁-C₂₀alkoxyalkyl, wherein said aryl group is phenyl or naphthyl;

(2) a nitrogen containing ring represented by the following graphicformula:

 wherein Y is selected from the group consisting of —CH₂—, —CH(R₁₇)—,—C(R₁₇)(R₁₇)—, —CH(aryl)—, —C(aryl)₂—, and —C(R₁₇)(aryl)—, and X isselected from the group consisting of —Y—, —O—, —S—, —S(O)—, —S(O₂)—,—NH—, —NR₁₇— and —N-aryl, wherein R₁₇ is C₁-C₆ alkyl, said arylsubstituent is phenyl or naphthyl, m is the integer 1, 2 or 3, and p isthe integer 0, 1, 2, or 3, provided that when p is 0, X is Y; and

(3) a group represented by the following graphic formulae:

wherein R₁₉, R₂₀ and R₂₁ are each hydrogen, C₁-C₅ alkyl, phenyl ornaphthyl, or the groups R₁₉ and R₂₀ may come together to form a ring of5 to 8 carbon atoms (including the ring carbon atoms). For example, whenR₁₉ and R₂₀ come together to form a ring of 6 carbon atoms on the grouprepresented by graphic formula IIB, the resulting unsaturated group iscarbazol-9-yl and the saturated group is tetrahydrocarbazol-9-yl. R₁₈ isC₁-C₆ alkyl, C₁-C₆ alkoxy, fluoro or chloro; or

(iii) R₅ and R₆ together form the following graphic formula;

wherein J and K are each oxygen or the group —NR₁₅—, R₁₅, R₁₉ and R₂₀being as defined before. Preferably, R₅ and R₆ and optionally R₄, areeach selected from the group consisting of:

(i) the group, —OR₈′, wherein R₈′ is —CH(R₉)Q and Q is —CN; and

(ii) a group selected from:

(1) —N(R₁₅)R₁₆, wherein R₁₅ and R₁₆ are C₁-C₄ alkyl;

(2) a nitrogen containing ring represented by graphic formula IIAwherein Y is —CH₂— or —CH(R₁₇)—, X is —O—, —NH— or —NR₁₇— and R₁₇ isC₁-C₃ alkyl; or

(3) a group represented by graphic formulae IIB or IIC wherein R₁₉, R₂₀and R₂₁ are each hydrogen or C₁-C₃ alkyl and R₁₈ is C₁-C₃ alkyl; or

(iii) R₅ and R₆ together form the group represented by graphic formulaeIID and IIE wherein J and K are oxygen. More preferably, R₄, R₅ and R₆are each C₁-C₃ alkoxy.

B and B′ in graphic formula I may each be selected from the groupconsisting of:

(i) mono-T-substituted phenyl;

(ii) the unsubstituted, mono-, di-, and tri-substituted aryl groups,phenyl and naphthyl;

(iii) 9-julolidinyl and the unsubstituted, mono- and di-substitutedaromatic heterocyclic groups pyridyl, furanyl, benzofuran-2-yl,benzofuran-3-yl, thienyl, benzothien-2-yl, benzothien-3-yl,dibenzofuranyl, dibenzothienyl, carbazoyl, benzopyridyl, indolinyl andfluorenyl, each of said aryl and aromatic heterocyclic substituents inthese parts (ii) and (iii) being selected from the group consisting ofhydroxy, aryl, i.e., phenyl and naphthyl, mono(C₁-C₆)alkoxyaryl,di(C₁-C₆)alkoxyaryl, mono(C₁-C₆)alkylaryl, di(C₁-C₆)alkylaryl,chloroaryl, fluoroaryl, C₃-C₇ cycloalkylaryl, C₃-C₇ cycloalkyl, C₃-C₇cycloalkyloxy_(, C) ₃-C₇ cycloalkyloxy(C₁-C₆)alkyl, C₃-C₇cycloalkyloxy(C₁-C₆)alkoxy, aryl(C₁-C₆)alkyl, aryl(C₁-C₆)alkoxy,aryloxy, aryloxy(C₁-C₆)alkyl, aryloxy(C₁-C₆)alkoxy, mono- anddi-(C₁-C₆)alkylaryl(C₁-C₆)alkyl, mono- anddi-(C₁-C₆)alkoxyaryl(C₁-C₆)alkyl, mono- anddi-(C₁-C₆)alkylaryl(C₁-C₆)alkoxy, mono- anddi-(C₁-C₆)alkoxyaryl(C₁-C₆)alkoxy, amino, mono(C₁-C₆)alkylamino,di(C₁-C₆)alkylamino, diarylamino, piperazino, N-(C₁-C₆)alkylpiperazino,N-arylpiperazino, aziridino, indolino, piperidino, morpholino,thiomorpholino, tetrahydroquinolino, tetrahydroisoquinolino, pyrrolidyl,C₁-C₆ alkyl, C₁-C₆ chloroalkyl, C₁-C₆ fluoroalkyl, C₁-C₆ alkoxy,mono(C₁-C₆)alkoxy(C₁-C₄)alkyl, acryloxy, methacryloxy, bromo, chloro andfluoro, each aryl group described for said aryl or heteroaromaticsubstituent being phenyl or naphthyl;

(iv) the unsubstituted or mono-substituted groups pyrazolyl, imidazolyl,pyridyl, pyrazolinyl, imidazolinyl, pyrrolinyl, phenothiazinyl,phenoxazinyl, phenazinyl or acridinyl, each of said substituents in thispart (iv) being selected from the group consisting of C₁-C₆ alkyl, C₁-C₆alkoxy, phenyl, fluoro, chloro and bromo;

(v) monosubstituted phenyl, having a substituent at the para positionthat is a linking group, —(CH₂)_(t)— or —O—(CH₂)_(t)—, wherein t is theinteger 1, 2, 3, 4, 5 or 6, connected to an aryl group, e.g. phenyl ornaphthyl, which is a member of another photochromic naphthopyran, suchas naphtho[2,1-b]pyran or naphtho[1,2-b]pyran;

(vi) the groups represented by the following graphic formulae:

 wherein A may be methylene or oxygen and D may be oxygen or substitutednitrogen, provided that when D is substituted nitrogen, A is methylene,said nitrogen substituents being selected from the group consisting ofhydrogen, C₁-C₆ alkyl, and C₂-C₆ acyl; each R₂₄ is C₁-C₆ alkyl, C₁-C₆alkoxy, hydroxy, chloro or fluoro; R₂₂ and R₂₃ are each hydrogen orC₁-C₆ alkyl; and q is the integer 0, 1, or 2;

(vii) C₁-C₆ alkyl, C₁-C₆ chloroalkyl, C₁-C₆ fluoroalkyl, C₁-C₆alkoxy(C₁-C₄)alkyl, C₃-C₆ cycloalkyl,mono(C₁-C₆)alkoxy(C₃-C₆)cycloalkyl, mono(C₁-C₆)alkyl(C₃-C₆)cycloalkyl,chloro(C₃-C₆)cycloalkyl, fluoro(C₃-C₆)cycloalkyl and C₄-C₁₂bicycloalkyl; and

(viii) the group represented by the following graphic formula:

 wherein L in graphic formula IIH may be hydrogen or C₁-C₄ alkyl and Min graphic formula IIH may be selected from the unsubstituted, mono-,and di-substituted members of the group consisting of naphthyl, phenyl,furanyl, and thienyl, each of said group substituents in this part(viii) being C₁-C₄ alkyl, C₁-C₄ alkoxy, fluoro, or chloro.

Alternatively, B and B′ may together form fluoren-9-ylidene, mono-, ordi-substituted fluoren-9-ylidene or form a member selected from thegroup consisting of saturated C₃-C₁₂ spiro-monocyclic hydrocarbon rings,e.g., cyclopropylidene, cyclobutylidene, cyclopentylidene,cyclohexylidene, cycloheptylidene, cyclooctylidene, cyclononylidene,cyclodecylidene cycloundecylidene, cyclododecylidene; saturated C₇-C₁₂spiro-bicyclic hydrocarbon rings, e.g., bicyclo[2.2.1]heptylidene, i.e.,norbornylidene, 1,7,7-trimethyl bicyclo[2.2.1]heptylidene, i.e.,bornylidene, bicyclo[3.2.1]octylidene, bicyclo[3.3.1]nonan-9-ylidene,bicyclo[4.3.2]undecane, and saturated C₇-C₁₂ spiro-tricyclic hydrocarbonrings, e.g., tricyclo[2.2.1.0^(2,6)]heptylidene,tricyclo[3.3.1.1^(3,7)]decylidene, i.e., adamantylidene, andtricyclo[5.3.1.1^(2,6)]dodecylidene, each of said fluoren-9-ylidenesubstituents being selected from the group consisting of C₁-C₄ alkyl,C₁-C₄ alkoxy, fluoro and chloro.

More preferably, B and B′ are each selected from the group consistingof: (i) phenyl, mono-substituted phenyl, and di-substituted phenyl,preferably substituted in the meta and/or para positions; (ii) theunsubstituted, mono- and di-substituted aromatic heterocyclic groupsfuranyl, benzofuran-2-yl, thienyl, benzothien-2-yl and dibenzofuranyl,each of said phenyl and aromatic heterocyclic substituents beingselected from the group consisting of hydroxy, amino,mono(C₁-C₃)alkylamino, di(C₁-C₃)alkylamino, piperidino, morpholino,pyrryl, C₁-C₃ alkyl, C₁-C₃ chloroalkyl, C₁-C₃ fluoroalkyl, C₁-C₃ alkoxy,mono(C₁-C₃)alkoxy(C₁-C₃)alkyl, fluoro and chloro; (iii) the groupsrepresented by the graphic formulae IIF and IIG, wherein A is methyleneand D is oxygen, R₂₄ is C₁-C₃ alkyl or C₁-C₃ alkoxy, R₂₂ and R₂₃ areeach hydrogen or C₁-C₄ alkyl; and q is the integer 0 or 1; (iv) C₁-C₄alkyl; and (v) the group represented by the graphic formula IIH whereinL is hydrogen or methyl and M is phenyl or mono-substituted phenyl, saidphenyl substituent being selected from the group consisting of C₁-C₃alkyl, C₁-C₃ alkoxy, and fluoro; or (vi) B and B′ taken together formfluoren-9-ylidene, mono-substituted fluoren-9-ylidene or a memberselected from the group consisting of saturated C₃-C₈ spiro-monocyclichydrocarbon rings, saturated C₇-C₁₀ spiro-bicyclic hydrocarbon rings,and saturated C₇-C₁₀ spiro-tricyclic hydrocarbon rings, saidfluoren-9-ylidene substituent being selected from the group consistingof C₁-C₃ alkyl, C₁-C₃ alkoxy, fluoro and chloro.

Most preferably, B and B′ are each selected from the group consisting of(i) phenyl, mono- and di-substituted phenyl, (ii) the unsubstituted,mono- and di-substituted aromatic heterocyclic groups furanyl,benzofuran-2-yl, thienyl, benzothien-2-yl and dibenzofuranyl, each ofsaid phenyl and aromatic heterocyclic substituents being selected fromthe group consisting of hydroxy, C₁-C₃ alkyl, C₁-C₃ alkoxy, fluoro andchloro; and (iii) the group represented by graphic formula IIF, whereinA is methylene and D is oxygen, R₂₄ is C₁-C₃ alkyl or C₁-C₃ alkoxy, R₂₂and R₂₃ are each hydrogen or C₁-C₃ alkyl, and q is the integer 0 or 1;or (iv) B and B′ taken together form fluoren-9-ylidene, adamantylidene,bornylidene, norbornylidene, or bicyclo[3.3.1]nonan-9-ylidene.

Compounds represented by graphic formula I having certain of thesubstituents R₁-R₇ described hereinbefore, may be prepared by thefollowing Reactions A through F and I through L. Methods for thepreparation of compounds represented by graphic formula I wherein R₅ isan amino group, are included in Reaction G. Methods for preparingcompounds of graphic formula I wherein R₅ and R₆ together form aheterocyclic ring are included in Reaction H. Reactions M and N describethe preparation of compounds of formula I wherein R₁ and/or R₂ are aminogroups. Reactions O and P describe methods for preparing the compoundsof graphic formula I when R₁ and R₂ come together to formspirocarbocyclic or spiroheterocyclic groups.

Methods for the preparation of compounds wherein R₁, R₂, B and/or B′ isthe polyalkoxylated group T are described in U.S. Pat. No. 5,961,892,which disclosure is incorporated herein by reference. Methods for thepreparation of compounds wherein R₁, R₂, B and/or B′ is thepolymerizable polyalkoxylated group T are described in U.S. applicationSer. No. 09/151,911, filed Sep. 11, 1998, which application isincorporated herein by reference.

With reference to the following reactions, compounds represented bygraphic formula V, VA, or VB are either purchased or prepared byFriedel-Crafts methods shown in Reaction A using an appropriatelysubstituted or unsubstituted benzoyl chloride of graphic formula IV witha commercially available substituted or unsubstituted benzene compoundof graphic formula III. See the publication Friedel-Crafts and RelatedReactions, George A. Olah, Interscience Publishers, 1964, Vol. 3,Chapter XXXI (Aromatic Ketone Synthesis), and “RegioselectiveFriedel-Crafts Acylation of 1,2,3,4-Tetrahydroquinoline and RelatedNitrogen Heterocycles: Effect on NH Protective Groups and Ring Size” byIshihara, Yugi et al, J. Chem. Soc., Perkin Trans. 1, pages 3401 to3406, 1992.

In Reaction A, the compounds represented by graphic formulae III and IVare dissolved in a solvent, such as carbon disulfide or methylenechloride, and reacted in the presence of a Lewis acid, such as aluminumchloride or tin tetrachloride, to form the corresponding substitutedbenzophenone represented by graphic formula V (VA in Reaction B or VB inReaction C). R and R′ represent possible substituents, as describedhereinbefore with respect to B and B′ of graphic formula I.

In Reaction B, the substituted or unsubstituted ketone represented bygraphic formula VA, in which B and B′ may represent groups other thansubstituted or unsubstituted phenyl, as shown in graphic formula V, isreacted with sodium acetylide in a suitable solvent, such as anhydroustetrahydrofuran (THF), to form the corresponding propargyl alcoholrepresented by graphic formula VI. Propargyl alcohols having B or B′groups other than substituted and unsubstituted phenyl may be preparedfrom commercially available ketones or ketones prepared via reaction ofan acyl halide with a substituted or unsubstituted benzene, naphthaleneor heteroaromatic compound, e.g., 9-julolidinyl. Propargyl alcoholshaving a B or B′ group represented by graphic formula IIH may beprepared by the methods described in U.S. Pat. No. 5,274,132, column 2,lines 40 to 68.

In Reaction C, a substituted benzophenone represented by graphic formulaVB is reacted with an ester of succinic acid such as dimethyl succinaterepresented by graphic formula VII. Addition of the reactants to asolvent, e.g., toluene, containing potassium t-butoxide or sodiumhydride as the base yields the Stobbe condensation half esterrepresented by graphic formula VIII. A mixture of cis and trans halfesters forms, which then undergoes cyclodehydration in the presence ofacetic anhydride to form a mixture of acetoxynaphthalenes. Furtherpurification to isolate the distinct isomer represented by graphicformula IX may be required. This product is hydrolyzed in an aqueousalcoholic solution of base, such as sodium hydroxide, followed bytreatment with aqueous hydrochloric acid (H⁺) to form thecarboxynaphthol represented by graphic formula X.

In Reaction D, the carboxynaphthol represented by graphic formula X iscyclized by heating, e.g., from about 110 to about 200° C., in thepresence of an acid, such as dodecylbenzene sulfonic acid (DBSA), to ahydroxy-substituted benzo-fused fluorenone represented by graphicformula XI. See the article by F. G. Baddar et al, in the J. Chem. Soc.,page 986, 1958.

Coupling of the compound represented by graphic formula XI with apropargyl alcohol represented by graphic formula VI in the presence of acatalytic amount of an acid, e.g., DBSA, results in the indeno-fusednaphthopyran represented by graphic formula IA. The reduction of thecompound represented by graphic formula XI via a Wolff-Kishner reductionresults in the compound represented by graphic formula XIA. Coupling ofthe compound represented by graphic formula XIA with a propargyl alcoholrepresented by graphic formula VI results in the indeno-fusednaphthopyran represented by graphic formula IB.

In Reaction E, further methods for preparing compounds represented bygraphic formula I having different R₁ and R₂ substituents are described.Starting with the compound represented by graphic formula IA, reductionwith lithium aluminum hydride (LAH) results in the compound representedby graphic formula IC. Other methods for reducing the carbonyl group aredescribed in the text The Chemistry of the Carbonyl Group, Chapter 11,Saul Patai, Editor, 1966, Interscience Publishers.

The reaction of the compound represented by graphic formula IC with anacid chloride having a substituent V results in the compound representedby graphic formula ID. Another pathway for incorporating different R₁and R₂ substituents on the compound represented by graphic formula IA isby reacting the compound (IA) with a Grignard (R₁MgX) or lithium reagenthaving a substituent R₁ to produce the compound represented by graphicformula IE. Subsequent reaction of the compound represented by graphicformula IE with an alcohol having a substituent R₈ in the presence of anacid such as hydrochloric acid results in the compound represented bygraphic formula IF.

An alternate method of producing compounds of graphic formula I isdescribed in Reaction F. In Reaction F, the acetoxynaphthalenerepresented by graphic formula IX (from Reaction C) is treated withhydrochloric acid (H⁺) and methanol to form the carbomethoxy naphtholrepresented by graphic formula XII. When R₁ and R₂ are the same, thesesubstituents are introduced by reacting the compound represented bygraphic formula XII with a Grignard reagent (R₁MgX) followed by heatingin the presence of an acid such as DBSA to cyclize the compound yieldinga compound represented by graphic formula XIII. Coupling of the compoundrepresented in graphic formula XIII with a propargyl alcohol representedby graphic formula VI results in the indeno-fused naphthopyranrepresented by graphic formula IG.

Reaction G along with the procedures described in Reactions C through Eare followed to produce amino substituted indeno-fused naphthopyrans.

In Reaction G, the benzophenone represented by graphic formula VC isreacted with a lithium salt of an amine represented by graphic formulaXIV in a solvent such as tetrahydrofuran (THF) to produce the aminosubstituted benzophenone represented by graphic formula XV. As describedin Reaction C, treatment of compound XV with dimethyl succinate toproduce the corresponding ester, followed by cyclization with aceticanhydride produces an amino substituted acetoxynaphthalene. Methanolysisof the amino substituted acetoxynaphthalene, as described in Reaction Cproduces the corresponding amino substituted naphthol. The aminosubstituted naphthol is then coupled with propargyl alcohol as describedin Reaction D and may be further modified as described in Reactions Eand F to produce amino substituted naphthopyrans.

Reaction H along with the procedures described in Reactions C through Emay be followed to produce indeno-fused naphthopyrans having aheterocyclic ring fused thereto. In Reaction H, the compoundsrepresented by graphic formulae IIIA and IVA are dissolved in a solvent,such as carbon disulfide or methylene chloride, and reacted in thepresence of a Lewis acid, such as aluminum chloride or tintetrachloride, to form the corresponding substituted benzophenonerepresented by graphic formula VD. As described in Reaction C, treatmentof compound VD with dimethyl succinate to produce the correspondingester, followed by cyclization with acetic anhydride produces aheterocyclic fused acetoxynaphthalene Methanolysis of the heterocyclicfused acetoxynaphthalene as described in Reaction C produces thecorresponding heterocyclic fused naphthol. The naphthol is then coupledwith propargyl alcohol, as described in Reaction D, and the product maybe further modified as described in Reactions E and F to produceheterocyclic fused naphthopyrans.

An alternative method of producing the carboxynaphthol of graphicformula X from the half ester of graphic formula VIII (from Reaction C)is presented in Reaction I. Compound VIII is reduced using a Raney alloy(NiAl₂) in the presence of aqueous sodium hydroxide to produce thediacid represented by graphic formula XVI. An intramolecularFriedel-Crafts cyclization is carried out by forming the correspondinganhydride, followed by treatment of the anhydride with a Lewis acid,such as aluminum chloride, to provide the keto-acid represented bygraphic formula XVII. Aromatization of compound XVII is initiated usingbasic methanol (MeOH) in the presence of oxygen to yield the naphthoicacid of graphic formula X. Compound X is used as described above inReactions D and E to produce the indeno-fused naphthols of graphicformula IA through IF.

Yet another method of producing the indeno-fused naphthol of graphicformula XI is described in Reaction J. Friedel-Crafts acylation of asubstituted benzene represented by graphic formula IVB with succinicanhydride represented by graphic formula XVIII using aluminum chlorideyields the compound represented by graphic formula XIX. Esterificationof compound XIX yields the compound represented by graphic formula XX.Upon Aldol-type condensation of compound XX with the benzaldehyderepresented by graphic formula XXI under basic conditions, such as withsodium methoxide, the enone-acid represented by graphic formula XXII isproduced. Cyclization of compound XXII with a Lewis acid such asaluminum chloride followed by hydrolysis yields the indanone representedby graphic formula XXIII. Compound XXIII is converted to the compoundrepresented by graphic formula XXIV by treatment with oxalyl chloride(COCl)₂ followed by cyclization using a Lewis acid such as stannouschloride or both steps can be replaced by acid promoted cyclizationusing phosphoric acid. Compound XXIV is oxidized using methanolic sodiumhydroxide with oxygen sparging to produce the indeno-fused naphthol ofgraphic formula XI. This reaction mechanism is further described by C.F. Koelsch in the Journal of Organic Chemistry, volume 26, page 2590,1961.

In Reaction K, the substituted ketoester represented 5 by graphicformula XXV and an aryl aldehyde represented by graphic formula XXVI aretreated with a base, such as sodium methoxide, under conditions of anAldol-type condensation to produce the substituted3-keto-4-aryl-3-butenoic acid represented by graphic formula XXVII. R₁′may represent an aromatic substituent or a non-aromatic substituent. Thesubstituted 3-keto-4-aryl-3-butenoic acid represented by graphic formulaXXVII is treated with acetic anhydride to produce the substituted3-keto-1-acetoxynaphthalene represented by graphic formula XXVIII. Theacetate group of this compound is removed under conditions of basic oracidic hydrolysis to yield the substituted 3-keto-1-hydroxynaphthalenerepresented by graphic formula XXIX. Addition of an excess ofnucleophile, e.g., Grignard reagents, lithium reagents or cyanide anion,produces the compound represented by graphic formula XXX. R₂′ mayrepresent an aromatic substituent or a non-aromatic substituent providedthat either R₁′ or R₂′ or both R₁ ¹ and R₂′ are aromatic substituents,preferably phenyl. Compound XXX is a tertiary alcohol or, in the casewhen hydride is used as the nucleophile, a secondary alcohol.

In Reaction L the compound represented by the graphic formula XXXA issubjected to dehydration under acidic conditions as described by S.Patai and S. Dayagi, J.Chem. Soc, 1962, pp. 716-723; and G. Chuchani, J.Chem. Soc., 1959, pp. 1753-1756; to yield the indeno-fused naphtholrepresented by graphic formula XXXI. The indeno-fused naphthol XXXI canbe further modified by replacing the hydrogen adjacent to R₂ withhydroxy or alkoxy group via oxidation. The resulting naphthol XXXII canbe used to produce the indeno-fused naphthopyrans of graphic formula I(where either R₁ or R₂ is a hydroxy or an alkoxy group) by the stepspreviously described for coupling with propargyl alcohol in Reaction D.Naphthol XXXI can be used to produce the indeno-fused naphthopyrans ofgraphic formula I wherein one or both substituents R₁ and R₂ arehydrogen by the steps previously described for coupling with propargylalcohol in Reaction D. Indeno-fused naphthopyrans of graphic formula Ihaving either R₁ or R₂, or both R₁ and R₂ as hydrogen can be furthermodified by replacing the hydrogen adjacent to R₂ with an alkyl groupvia alkylation with alkyl halides under basic conditions to yieldindeno-fused naphthopyrans I where either R₁ or R₂, or both R₁ and R₂are alkyl groups.

Reaction M or N may be followed to produce indeno-fused naphthopyranswhere R₁ and/or R₂ are an amine group. In Reaction M, the compoundrepresented by graphic formula XI from Reaction D is coupled with aprimary aliphatic amine (H₂NAlk) or primary aromatic amine (H₂NAr), withthe aliphatic amino shown below by example, under dehydrating conditionseither azeotropically by distillation or with a drying agent such astitanium tetrachloride yielding the corresponding fluoreniminerepresented by graphic formula XXXIII. Compound XXXIII may be reducedusing sodium borohydride to produce the corresponding amino fluorenerepresented by graphic formula XXXIVA. Compound XXXIII may also bereductively alkylated using an organolithium compound Alk—Li or Ar—Li ora Grignard reagent to yield the compounds represented by graphicformulae XXXIVB and XXXIVC. When the primary aliphatic amino (H₂NAlk) isbenzylamino, treatment of compound XXXIII (having a benzyl substituentas Alk) with a base, such as sodium hydride, and a chloroformatederivative, such as ClC(O)W (wherein W is certain of the substituentsdescribed hereinbefore), yields the corresponding amino esterrepresented by graphic formula XXXIVD.

In Reaction N, the compound represented by graphic formula XI is treatedwith a secondary amine, e.g. dialiphatic amine (HN(Alk)₂), a diaromaticamine (HN(Ar)₂) or an aliphatic aromatic amine (HNAlkAr), to produce thecorresponding hemiaminal represented by graphic formula XXXV. Uponaddition of excess of the amino, such as HN(Alk)₂, the aminalrepresented by graphic formula XXXIVE is formed. Coupling of each ofcompounds XXXIVA through XXXIVE with propargyl alcohol as described inReaction D results in the corresponding indeno-fused naphthopyrans.Alternatively, the oxo substituted indeno-fused naphthopyran representedby graphic formula IA (Reaction D) may be treated as described inReactions M and N via amination and reductive amination to produceindeno-fused naphthopyrans having amino groups at the R₁ and/or R₂substituents.

In Reaction O, the indeno-fused naphthopyran represented by graphicformula IA is first reacted with compound XXXVI and then cyclized underacidic conditions (H⁺) to produce the compound represented by graphicformula IH. Substituents R₂₂ and R₂₃ are the same as previouslydescribed.

In Reaction P, the indeno-fused naphthopyran represented by graphicformula IA is first reacted with compound XXXVII and then cyclized underacidic conditions (H⁺) to produce the compound represented by graphicformula IJ. E in compound XXXVII may be selected from the groups, (—O—),(—CH₂—), and (—CH═CH—) and s is an integer of from 0 to 2. When E is(—CH₂—), s equals 1-2, when E is (—CH═CH—), s equals 1 and when s equals0, E is a carbon-carbon bond.

Compounds represented by graphic formula I may be used in thoseapplications in which organic photochromic substances may be employed,such as optical lenses, e.g., vision correcting ophthalmic lenses, planolenses and contact lenses, face shields, goggles, visors, camera lenses,windows, automotive windshields, aircraft and automotive transparencies,e.g., T-roofs, sidelights and backlights, plastic films and sheets,textiles and coatings, e.g., coating compositions such as paints, andverification marks on security documents, e.g., documents such asbanknotes, passports and drivers' licenses for which authentication orverification of authenticity may be desired. Naphthopyrans representedby graphic formula I exhibit blended color changes from colorless tocolors of gray, brown or green. These blended color changes are a resultof one absorption band (Band “A”) in the 420-500 nm region and anotherabsorption band (Band “B”) in the 500-650 nm region.

Examples of contemplated naphthopyran compounds within the scope of theinvention are the following:

(a)3,3-di(4-methoxyphenyl)-6,7,10,11-tetramethoxy-13,13-dimethyl-3H,13H-indeno[2,1-f]naphtho[1,2-b]pyran;

(b)3-phenyl-3-(4-morpholinophenyl)-6,7,10,11-tetramethoxy-13,13-dimethyl-3H,13H-indeno[2,1-f]naphtho[1,2-b]pyran;

(c)3,3-di(4-methoxyphenyl)-6,7,10,11-tetramethoxy-13-hydroxy-13-ethyl-3H,13H-indeno[2,1-f]naphtho[1,2-b]pyran;

(d)3,3-di(4-methoxyphenyl)-6,7-dimethoxy-13,13-dimethyl-3H,13H-indeno[2,1-f]naphtho[1,2-b]pyran;

(e)3,3-di(4-methoxyphenyl)-6,7-dimethoxy-13-hydroxy-13-ethyl-3H,13H-indeno[2,1-f]naphtho[1,2-b]pyran;

(f)3,3-di(4-methoxyphenyl)-6,7,10,11-tetramethoxy-13,13-diethyl-3H,13H-indeno[2,1-f]naphtho[1,2-b]pyran;

(g)3,3-di(4-methoxyphenyl)-6,7-dimethoxy-13-phenyl-3H,13H-indeno[2,1-f]naphtho[1,2-b]pyran;

(h)3-(4-methoxyphenyl)-3-(4-morpholinophenyl)-6,7-dimethoxy-13-phenyl-3H,13H-indeno[2,1-f]naphtho[1,2-b]pyran;

(i)3-(4-methoxyphenyl)-3-(4-morpholinophenyl)-6,7-dimethoxy-13,13-dimethyl-3H,13H-indeno[2,1-f]naphtho[1,2-b]pyran;

(j)3-(4-methoxyphenyl)-3-(4-dimethylaminophenyl)-6,7-dimethoxy-13,13-dimethyl-3H,13H-indeno[2,1-f]naphtho[1,2-b]pyran;

(k)3,3-di(4-methoxyphenyl)-6,7,8-trimethoxy-13-phenyl-3H,13H-indeno[2,1-f]naphtho[1,2-b]pyran;

(l)3-(4-methoxyphenyl)-3-(4-morpholinophenyl)-6,7,10,11-tetramethoxy-13-hydroxy-13-ethyl-3H,13H-indeno[2,1-f]naphtho[1,2-b]pyran;

(m)3-(4-methoxyphenyl)-3-(4-morpholinophenyl)-6,7,10,11-tetramethoxy-13-hydroxy-13-butyl-3H,13H-indeno[2,1-f]naphtho[1,2-b]pyran;

(n)3-(4-morpholinophenyl)-3-phenyl-6,7-dimethoxy-13-hydroxy-13-ethyl-3H,13H-indeno[2,1,-f]naphtho[1,2-b]pyran;

(o)3,3-di(4-methoxyphenyl)-6,7-dimethoxy-13-hydroxy-13-butyl-3H,13H-indeno[2,1,-f]naphtho[1,2-b]pyran;

(p)3-(4-morpholinophenyl)-3-phenyl-6,7-dimethoxy-13-hydroxy-13-butyl-3H,13H-indeno[2,1,-f]naphtho[1,2-b]pyran;

(q)3-(4-methoxyphenyl)-3-(4-morpholinophenyl)-6,7-dimethoxy-13-hydroxy-13-ethyl-3H,13H-indeno[2,1-f]naphtho[1,2-b]pyran;

(r)3-(4-methoxyphenyl)-3-(4-morpholinophenyl)-6,7-dimethoxy-13-ethyl-13-methoxy-3H,13H-indeno[2,1-f]naphtho[1,2-b]pyran;

(s)3-(4-methoxyphenyl)-3-(4-morpholinophenyl)-6,7-dimethoxy-13-hydroxy-13-methyl-3H,13H-indeno[2,1-f]naphtho[1,2-b]pyran;and

(t)3-(4-methoxyphenyl)-3-(4-morpholinophenyl)-6,7-dimethoxy-13-methoxy-13-methyl-3H,13H-indeno[2,1-f]naphtho[1,2-b]pyran.

Other than in the operating examples, or where otherwise indicated, allnumbers expressing wavelengths, quantities of ingredients or reactionconditions used herein are to be understood as modified in all instancesby the term “about”.

It is contemplated that the photochromic naphthopyrans of the presentinvention may each be used alone, in combination with othernaphthopyrans of the present invention, or in combination with one ormore other appropriate complementary organic photochromic materials,i.e., organic photochromic compounds having at least one activatedabsorption maxima within the range of between about 400 and 700nanometers, or substances containing the same, and may be incorporated,e.g., dissolved or dispersed, in a polymeric organic host material usedto prepare photochromic articles which color when activated to anappropriate hue.

Examples of complementary organic photochromic compounds include othernaphthopyrans and indenonaphthopyrans, chromenes and oxazines,substituted 2H-phenanthro[4,3-b]pyran and 3H-phenanthro[1,2-b]pyrancompounds, benzopyran compounds having substituents at the 2-position ofthe pyran ring and mixtures of such photochromic compounds. Suchphotochromic compounds are described in U.S. Pat. Nos. 3,562,172;3,567,605; 3,578,602; 4,215,010; 4,342,668; 4,816,584; 4,818,096;4,826,977; 4,880,667; 4,931,219; 5,066,818; 5,238,981; 5,274,132;5,384,077; 5,405,958; 5,429,774; 5,458,814, 5,466,398; 5,514,817;5,552,090; 5,552,091; 5,565,147; 5,573,712; 5,578,252; 5,637,262;5,645,767; 5,656,206; 5,658,500; 5,658,501; 5,674,432 and 5,698,141.Spiro(indoline)pyrans are also described in the text, Techniques inChemistry, Volume III, “Photochromism”, Chapter 3, Glenn H. Brown,Editor, John Wiley and Sons, Inc., New York, 1971.

The complementary organic photochromic materials may also includepolymerizable photochromic compounds, such as those disclosed in U.S.Pat. Nos. 4,719,296; 5,166,345; 5,236,958; 5,252,742; 5,359,035; and5,488,119.

Other complementary photochromic substances contemplated aremetal-dithiozonates, e.g., mercury dithizonates which are described in,for example, U.S. Pat. No. 3,361,706; and fulgides and fulgimides, e.g.,the 3-furyl and 3-thienyl fulgides and fulgimides, which are describedin U.S. Pat. No. 4,931,220 at column 20, line 5 through column 21, line38.

The disclosures relating to such photochromic compounds in theaforedescribed patents are incorporated herein, in toto, by reference.The photochromic articles of the present invention may contain onephotochromic compound or a mixture of photochromic compounds, asdesired.

The photochromic compounds of the present invention may be associatedwith a polymeric organic host material or other substrate by variousmeans. They may be incorporated, i.e., dissolved and/or dispersed, intothe host material, polymerized with other components of the hostmaterial, and/or incorporated into a coating applied to a substrate,e.g., a polymeric coating applied to one surface of the polymericorganic host material.

Each of the photochromic substances described herein may be used inamounts (or in a ratio) such that an organic host material or substrateto which the photochromic compounds or mixture of compounds isassociated, exhibits a desired resultant color, e.g., a substantiallyneutral color when activated with unfiltered sunlight, i.e., as near aneutral color as possible given the colors of the activated photochromiccompounds. Neutral gray and neutral brown colors are preferred. Furtherdiscussion of neutral colors and ways to describe colors may be found inU.S. Pat. No. 5,645,767 column 12, line 66 to column 13, line 19.

The amount of the photochromic naphthopyrans to be applied to orincorporated into a coating composition or host material is not criticalprovided that a sufficient amount is used to produce a photochromiceffect discernible to the naked eye upon activation. Generally suchamount can be described as a photochromic amount. The particular amountused depends often upon the intensity of color desired upon irradiationthereof and upon the method used to incorporate or apply thephotochromic compounds. Typically, the more photochromic compoundapplied or incorporated, the greater is the color intensity up to acertain limit.

The relative amounts of the aforesaid photochromic compounds used willvary and depend in part upon the relative intensities of the color ofthe activated species of such compounds, the ultimate color desired andthe method of application to the host material or substrate. Generally,the amount of total photochromic compound incorporated into or appliedto a photochromic optical host material may range from about 0.05 toabout 2.0, e.g., from 0.2 to about 1.0, milligrams per square centimeterof surface to which the photochromic compound is incorporated orapplied. The amount of photochromic material incorporated into a coatingcomposition may range from 0.1 to 40 weight percent based on the weightof the liquid coating composition.

The photochromic naphthopyrans of the present invention may beassociated with the host material by various methods described in theart. See, for example, column 13, lines 40 to 58 of U.S. Pat. No.5,645,767. Aqueous or organic solutions of the photochromic compoundsmay be used to incorporate the photochromic compounds into a polymericorganic host material or other materials such as textiles and polymericcoating compositions. Polymeric coating compositions may be applied tothe substrate using a coating process such as that described in U.S.Pat. No. 3,971,872, the disclosure of which is incorporated herein byreference.

Application of the polymeric coating may be by any of the methods usedin coating technology such as, for example, spray coating, spin coating,spread coating, curtain coating, dip coating, casting or roll-coatingand methods used in preparing overlays, such as the method of the typedescribed in U.S. Pat. No. 4,873,029, which is incorporated herein byreference. The application method selected also depends on the thicknessof the cured coating. Coatings having a thickness ranging from 1 to 50microns may be applied by conventional methods used in coatingtechnology. Coatings of a thickness greater than 50 microns may requiremolding methods typically used for overlays. A preferred coatingcomposition is polyurethane prepared from organic polyol(s) and anisocyanate. The photochromic substances of the present invention may bedissolved or dispersed within the organic polyol component or isocyanatecomponent of the polyurethane coating or may be added to a mixture ofthe polyurethane-forming components.

The host material will usually be transparent, but may be translucent oreven opaque. The host material need only be pervious to that portion ofthe electromagnetic spectrum, which activates the photochromicsubstance, i.e., that wavelength of ultraviolet (UV) light that producesthe open or colored form of the substance and that portion of thevisible spectrum that includes the absorption maximum wavelength of thesubstance in its UV activated form, i.e., the open form. Preferably, thehost color should not be such that it masks the color of the activatedform of the photochromic compounds, i.e., so the change in color isreadily apparent to the observer. Compatible tints may be applied to thehost material as described in U.S. Pat. No. 5,645,767 in column 13, line59 to column 14, line 3.

Most preferably, the polymeric organic host material is a solidtransparent or optically clear material, e.g., materials suitable foroptical applications, such as piano, ophthalmic and contact lenses,windows, automotive transparencies, e.g., windshields, aircrafttransparencies, plastic sheeting, polymeric films, etc.

Examples of polymeric organic host materials which may be used with thephotochromic compounds described herein include: polymers, i.e.,homopolymers and copolymers, of the bis(allyl carbonate) monomers,diethylene glycol dimethacrylate monomers, diisopropenyl benzenemonomers, ethoxylated bisphenol A dimethacrylate monomers, ethyleneglycol bismethacrylate monomers, poly(ethylene glycol) bismethacrylatemonomers, ethoxylated phenol bismethacrylate monomers, alkoxylatedpolyhydric alcohol acrylate monomers, such as ethoxylated trimethylolpropane triacrylate monomers, urethane acrylate monomers, such as thosedescribed in U.S. Pat. No. 5,373,033, and vinylbenzene monomers, such asthose described in U.S. Pat. No. 5,475,074 and styrene; polymers, i.e.,homopolymers and copolymers, mono- or polyfunctional, e.g., di- ormulti-functional, acrylate and/or methacrylate monomers, poly(C₁-C₁₂alkyl methacrylates), such as poly(methyl methacrylate),poly(oxyalkylene)dimethacrylate, poly(alkoxylated phenol methacrylates),cellulose acetate, cellulose triacetate, cellulose acetate propionate,cellulose acetate butyrate, poly(vinyl acetate), poly(vinyl alcohol),polyvinyl chloride), poly(vinylidene chloride), polyurethanes,polythiourethanes, thermoplastic polycarbonates, polyesters,poly(ethylene terephthalate), polystyrene, poly(alpha methylstyrene),copoly(styrene-methyl methacrylate), copoly(styrene-acrylonitrile),polyvinylbutyral and polymers, i.e., homopolymers and copolymers, ofdiallylidene pentaerythritol, particularly copolymers with polyol (allylcarbonate) monomers, e.g., diethylene glycol bis(allyl carbonate), andacrylate monomers, e.g., ethyl acrylate, butyl acrylate. Furtherexamples of polymeric organic host materials are disclosed in the U.S.Pat. No. 5,753,146, column 8, line 62 to column 10, line 34, whichdisclosure is incorporated herein by reference.

Transparent copolymers and blends of transparent polymers are alsosuitable as host materials. Preferably, the host material or substratefor the photochromic polymeric coating composition is an optically clearpolymerized organic material prepared from a thermoplastic polycarbonateresin, such as the carbonate-linked resin derived from bisphenol A andphosgene, which is sold under the trademark, LEXAN; a polyester, such asthe material sold under the trademark, MYLAR; a poly(methylmethacrylate), such as the material sold under the trademark, PLEXIGLAS;polymerizates of a polyol(allyl carbonate) monomer, especiallydiethylene glycol bis(allyl carbonate), which monomer is sold under thetrademark CR-39, and polymerizates of copolymers of a polyol (allylcarbonate), e.g., diethylene glycol bis(allyl carbonate), with othercopolymerizable monomeric materials, such as copolymers with vinylacetate, e.g., copolymers of from 80-90 percent diethylene glycolbis(allyl carbonate) and 10-20 percent vinyl acetate, particularly 80-85percent of the bis(allyl carbonate) and 15-20 percent vinyl acetate, andcopolymers with a polyurethane having terminal diacrylate functionality,as described in U.S. Pat. Nos. 4,360,653 and 4,994,208; and copolymerswith aliphatic urethanes, the terminal portion of which contain allyl oracrylyl functional groups, as described in U.S. Pat. No. 5,200,483;poly(vinyl acetate), polyvinylbutyral, polyurethane, polythiourethanes,polymers of members of the group consisting of diethylene glycoldimethacrylate monomers, diisopropenyl benzene monomers, ethoxylatedbisphenol A dimethacrylate monomers, ethylene glycol bismethacrylatemonomers, poly(ethylene glycol) bismethacrylate monomers, ethoxylatedphenol bismethacrylate monomers and ethoxylated trimethylol propanetriacrylate monomers; cellulose acetate, cellulose propionate, cellulosebutyrate, cellulose acetate butyrate, polystyrene and copolymers ofstyrene with methyl methacrylate, vinyl acetate and acrylonitrile.

More particularly contemplated is use of the photochromic naphthopyransof the present invention with optical organic resin monomers used toproduce optically clear coatings and polymerizates, i.e., materialssuitable for optical applications, such as for example plano, contactand ophthalmic lenses, windows, and automotive transparencies. Suchoptically clear polymerizates may have a refractive index that may rangefrom about 1.48 to about 1.75, e.g., from about 1.495 to about 1.66.

Specifically contemplated are polymerizates of optical resins sold byPPG Industries, Inc. under the CR-designation, e.g., CR-307 and CR-407,and polymerizates prepared for use as hard or soft contact lenses.Methods for 30 producing both types of contact lenses are disclosed inU.S. Pat. No. 5,166,345, column 11, line 52, to column 12, line 52,which disclosure is incorporated herein by reference. Additionalpolymerizates contemplated for use with the photochromic polyalkoxylatednaphthopyrans of the present invention are polymerizates used to formsoft contact lenses with high moisture content described in U.S. Pat.No. 5,965,630 and extended wear contact lenses described in U.S. Pat.No. 5,965,631, both disclosures of which are incorporated herein byreference.

The present invention is more particularly described in the followingexamples which are intended as illustrative only, since numerousmodifications and variations therein will be apparent to those skilledin the art.

EXAMPLE 1 Step 1

1,2-Dimethoxybenzene (74.5 grams) and a solution of 3,4-dimethoxybenzoylchloride (98.2 grams) in 500 milliliters (mL) of methylene chloride wereadded to a reaction flask fitted with a solid addition funnel under anitrogen atmosphere. Solid anhydrous aluminum chloride (71.8 grams) wasadded to the reaction mixture with occasionally cooling of the reactionmixture in an ice/water bath. The reaction mixture was stirred at roomtemperature for 3 hours. The resulting mixture was poured into 300 mL ofa 1:1 mixture of ice and 1N hydrochloric acid and stirred vigorously for15 minutes. The mixture was extracted twice with 100 mL methylenechloride. The organic layers were combined and washed with 50 mL of 10weight percent sodium hydroxide followed by 50 mL of water. Themethylene chloride solvent was removed by rotary evaporation to give ayellow solid. Recrystallization from 95 percent ethanol yielded 127grams of beige needles having a melting point of 146-147° C. A nuclearmagnetic resonance (NMR) spectrum showed the product to have a structureconsistent with 3,3′,4,4′-tetramethoxybenzophenone.

Step 2

Potassium t-butoxide (55.4 grams) and 100.0 grams of the product fromStep 1 were added to a reaction flask containing 600 mL of toluene undera nitrogen atmosphere. The mixture was heated to reflux and dimethylsuccinate (193 grams) was added dropwise over a 1 hour period. Themixture was refluxed for 5 hours and cooled to room temperature. Theresulting precipitate was collected by vacuum filtration and washed withfresh toluene to yield 143 grams of a beige powder. The powder wasdissolved in about 200 mL of water and acidified to pH 2 with 4Nhydrochloric acid. The acidic solution was extracted five times with 50mL of methylene chloride. The organic extracts were combined andconcentrated by rotary evaporation to produce 102 grams of a thick brownoil. An NMR spectrum showed the desired product to have a structureconsistent with 4,4-di(3,4-dimethoxyphenyl)-3-methoxycarbonyl-3-butenoicacid. This material was not purified further but was used directly inthe next step.

Step 3

The crude half-ester from Step 2 (100 grams), 60 mL of acetic anhydride,and 300 mL of toluene were added to a reaction flask under a nitrogenatmosphere. The reaction mixture was heated to 110° C. for 6 hours andcooled to room temperature, and the solvents (toluene and aceticanhydride) were removed by rotary evaporation. The residue was dissolvedin 300 mL of methylene chloride and 200 mL of water. Solid sodiumcarbonate was added to the biphasic mixture until bubbling ceased. Thelayers separated and the aqueous layer was extracted with two 50 mLportions of methylene chloride. The organic layers were combined and thesolvent (methylene chloride) was removed by rotary evaporation to yielda thick red oil. The oil was dissolved in warm methanol and chilled at0° C. for 2 hours. The resulting crystals were collected by vacuumfiltration, washed with cold methanol to produce 38.9 grams of a producthaving a melting point of 176-177° C. An NMR spectrum showed the productto have a structure consistent with1-(3,4-dimethoxyphenyl)-2-methoxycarbonyl-4-acetoxy-6,7-dimethoxynaphthalene.

Step 4

1-(3,4-Dimethoxyphenyl)-2-methoxycarbonyl-4-acetoxy-6,7-dimethoxynaphthalenefrom Step 3 (5 grams), 5 mL of 12M hydrochloric acid, and 30 mL ofmethanol were combined in a reaction flask and heated to reflux for 1hour. The reaction mixture was cooled and the resulting precipitate wascollected by vacuum filtration and washed with cold methanol yielding2.1 grams of beige needles having a melting point of 213-214° C. An NMRspectrum showed the product to have structure consistent with1-(3,4-dimethoxyphenyl)-2-methoxycarbonyl-4-hydroxy-6,7-dimethoxynaphthalene.

Step 5

A reaction flask was charged with1-(3,4-dimethoxyphenyl)-2-methoxycarbonyl-4-hydroxy-6,7-dimethoxynaphthalenefrom Step 4 (0.9 grams) under a nitrogen atmosphere. Anhydroustetrahydrofuran (20 mL) was added to the flask. The reaction mixture wascooled in a dry ice/acetone bath and 9 mL of a methyl magnesium chloridesolution (1M in tetrahydrofuran) was added dropwise over 15 minutes. Theresulting yellow reaction mixture was stirred at 0° C. for 2 hours andslowly warmed to room temperature. The reaction mixture was poured into50 mL of an ice/water mixture. Ether (20 mL) was added, and the layersseparated. The aqueous layer was extracted with two 20 mL portions ofether, and the organic portions were combined and washed with 30 mL ofwater. The organic layer was dried over anhydrous magnesium sulfate andconcentrated by rotary evaporation. The resulting oil was transferredinto a reaction vessel (fitted with a Dean-Stark trap) containing 50 mLof toluene to which two drops of dodecylbenzene sulfonic acid wereadded. The reaction mixture was heated to reflux for 2 hours and cooled.The toluene was removed via rotary evaporation to yield 0.73 grams of adark brown solid. An NMR spectrum showed the product to have a structureconsistent with7,7-dimethyl-5-hydroxy-2,3,9,10-tetramethoxy-7H-benzo[c]fluorene. Thismaterial was not purified further but was used directly in the nextstep.

Step 6

7,7-Dimethyl-5-hydroxy-2,3,9,10-tetramethoxy-7H-benzo[C]fluorene fromStep 5 (450 milligrams), 1,1-di(4-methoxyphenyl)-2-propyn-1-ol (345milligrams), two drops of dodecylbenzene sulfonic acid and 15 mL oftoluene were combined in a reaction vessel and stirred at ambienttemperature for three and one half hours. The reaction mixture wasdiluted with 15 mL of toluene and 15 mL of water. The organic layer wasseparated, dried over sodium sulfate, and concentrated by rotaryevaporation. The residue was chromatographed on a silica gel usingchloroform as the elutant. Photochromic fractions were collected,concentrated by rotary evaporation and the resulting solid wasrecrystallized from diethyl ether yielding 289 milligrams of needleshaving a melting point of 213-214° C. An NMR spectrum showed the productto have a structure consistent with3,3-di(4-methoxyphenyl)-6,7,10,11-tetramethoxy-13,13-dimethyl-3H,13H-indeno[2,1-f]naphtho[1,2-b]pyran.

EXAMPLE 2

The process of Example 1 was followed except that in Step 6,1-(4-morpholinophenyl)-1-phenyl-2-propyn-1-ol was used in place of1,1-di(4-dimethoxyphenyl)-2-propyn-1-ol. The resulting product waschromatographed on silica gel using ethyl acetate:hexane (1:1 v/v) asthe elutant. The desired product was recrystallized from hot ethanol(95%) to yield 239 milligrams of a product having a melting point of195-197° C. An NMR spectrum showed the product to have a structureconsistent with3-phenyl-3-(4-morpholinophenyl)-6,7,10,11-tetramethoxy-13,13-dimethyl-3H,13H-indeno[2,1-f]naphtho[1,2-b]pyran.

EXAMPLE 3 Step 1

The process of Example 1 was followed except that the1-(3,4-dimethoxyphenyl)-2-methoxycarbonyl-4-acetoxy-6,7-dimethoxynaphthaleneproduced in Step 3 (20.0 grams) was added to a reaction flask containing150 mL of a 10 weight percent aqueous sodium hydroxide solution and 15mL of methanol. The mixture was refluxed for 3 hours and cooled. Theaqueous layer was washed twice with methylene chloride, 50 mL each, andthe combined organic layers were extracted with 100 mL of water. Theaqueous layers were combined and acidified to pH 2 with an aqueoussolution of 6N hydrochloric acid. The aqueous layer was extracted fourtimes with 50 mL portions of methylene chloride. The methylene chloridelayers were combined and concentrated by rotary evaporation. Theresulting oil was crystallized from ethanol (95%) to yield 12.0 grams ofa beige powder having a melting point of 223-224° C. An NMR spectrumshowed the product to have a structure consistent with1-(3,4-dimethoxyphenyl)-4-hydroxy-6,7-dimethoxy-2-naphthoic acid.

Step 2

1-(3,4-Dimethoxyphenyl)-4-hydroxy-6,7-dimethoxy-2-naphthoic acid fromStep 1 (6.0 grams), 100 mL of toluene and 20 milligrams ofdodecylbenzene sulfonic acid were added to a reaction flask fitted witha Dean-Stark trap. The resulting mixture was heated to reflux for 5hours. A deep red solid precipitate formed. Two more portions ofdodecylbenzene sulfonic acid (50 milligrams and 500 milligrams) wereadded to the refluxing mixture at 3 hour intervals. The mixture wascooled and the solid was collected by vacuum filtration. Any unreactedstarting material was removed via digestion in boiling acetonitrile. Themixture was vacuum filtered to yield 4.45 grams of a product having amelting point range of 283-288° C. An NMR spectrum showed the product tohave a structure consistent with2,3,9,10-tetramethoxy-5-hydroxy-7H-benzo[C]fluoren-7-one.

Step 3

2,3,9,10-Tetramethoxy-5-hydroxy-7H-benzo[C]-fluoren-7-one from Step 2(2.19 grams) was added to a reaction flask containing1,1-di(4-methoxyphenyl)-2-propyn-1-ol (1.81 grams) and 75 mL ofchloroform and stirred at room temperature. Dodecylbenzene sulfonic acid(10 milligrams) was added and the reaction mixture immediately darkened.After stirring for one and one half hours, the chloroform was removed byrotary evaporation. The residue was dissolved in warm acetone andcrystals formed upon cooling to 0° C. Red colored needles (3.2 grams)having a melting point range of 249-254° C. were collected by vacuumfiltration. An NMR spectrum showed the product to have a structureconsistent with3,3-di(4-methoxyphenyl)-6,7,10,11-tetramethoxy-13-oxo-3H,13H-indeno[2,1-f]naphtho[1,2-b]pyran.

Step 4

3,3-Di(4-methoxyphenyl)-6,7,10,11-tetramethoxy-13-oxo-3H,13H-indeno[2,1-f]naphtho[1,2-b]pyranfrom Step 3 (3.0 grams) was added to a dry reaction flask under anitrogen atmosphere. Anhydrous tetrahydrofuran (50 mL) was added and thereaction mixture was cooled in a dry ice/acetone bath. Ethyl magnesiumchloride (7.2 mL of a 2M tetrahydrofuran solution) was added dropwiseover a one hour period, and the reaction was slowly warmed to roomtemperature. The reaction mixture was poured into a flask containing 100grams of ice, and this mixture was acidified to pH 3 with a 6N solutionof hydrochloric acid. The layers were separated and the aqueous layerwas extracted four times with 50 mL portions of diethyl ether. Theorganic layers were combined and the solvents (ether andtetrahydrofuran) were removed by rotary evaporation. The residue waschromatographed on silica gel using a 3:1 v/v mixture of hexane andethyl acetate as the elutant. The photochromic fractions were collected,concentrated by rotary evaporation and recrystallized from ethanol (95%)yielding 1.29 grams of the desired product. An NMR spectrum showed theproduct to have a structure consistent with3,3-di(4-methoxyphenyl)-6,7,10,11-tetramethoxy-13-hydroxy-13-ethyl-3H,13H-indeno[2,1-f]naphtho[1,2-b]pyran.

EXAMPLE 4 Step 1

The process of Step 1 of Example 1 was followed except that 92.5 gramsof 1,2-dimethoxy benzene and 89.7 grams of aluminum chloride were used.Benzoyl chloride (84.3 grams) was used instead of 3,4-dimethoxy benzoylchloride to yield 147 grams of a product having a melting point of103-105° C. An NMR spectrum showed the product to have a structureconsistent with 3,4-dimethoxy benzophenone.

Step 2

The process of Step 2 of Example 1 was followed except that3,4-dimethoxybenzophenone (90 grams) was used in place of3,3′4,4′-tetramethoxybenzophenone, and 144.8 grams of dimethyl succinate(dissolved in 300 mL of toluene), 62 grams of potassium t-butoxide, and700 mL of toluene were used. Instead of isolating the precipitate, 300mL of water was added to the reaction mixture and vigorously stirred for20 minutes. The aqueous and organic phases separated and the organicphase was extracted with 100 mL portions of water three times. Thecombined aqueous layers were washed with 50 mL portions of chloroformthree times. The aqueous layer was acidified to pH 2 with 6Nhydrochloric acid and a precipitate formed. The aqueous layer wasextracted with three 100 mL portions of chloroform. The organic extractswere combined and concentrated by rotary evaporation. An NMR spectrum ofthe resulting oil showed the product to have structures consistent witha mixture of (E and Z)4-(3,4-dimethoxyphenyl)-4-phenyl-3-methoxycarbonyl-3-butenoic acids.

Step 3

The process of Example 1, Step 3, was followed using the oil containing(E and Z) 4-(3,4-dimethoxyphenyl)-4-phenyl-3-methoxycarbonyl-3-butenoicacids (8.6 grams) from Step 2, which was added to a reaction flaskcontaining acetic anhydride (5 mL) and toluene (50 mL) An NMR spectrumshowed the recovered solid product to have structures consistent with amixture of1-(3,4-dimethoxyphenyl)-2-methoxycarbonyl-4-acetoxynaphthalene and1-phenyl-2-methoxycarbonyl-4-acetoxy-6,7-dimethoxynaphthalene. Theproduct mixture was used without further purification in subsequentreactions.

Step 4

The process of Example 1, Step 4 was followed except that the mixture of1-(3,4-dimethoxyphenyl)-2-methoxycarbonyl-4-acetoxynaphthalene and1-phenyl-2-methoxycarbonyl-4-acetoxy-6,7-dimethoxynaphthalene from Step3 was used. The product was purified by filtering through a plug ofsilica gel using a 2:1 mixture of hexane and ethyl acetate as theelutant. Concentration of the filtrate by rotary evaporation yielded 3.3grams of a beige solid. An NMR spectrum showed the product to havestructures consistent with a mixture of1-(3,4-dimethoxyphenyl)-2-methoxycarbonyl-4-hydroxynaphthalene and1-phenyl-2-methoxycarbonyl-4-hydroxy-6,7-dimethoxynaphthalene.

Step 5

The process of Example 1, Step 5 was followed except that the mixture of1-(3,4-dimethoxyphenyl)-2-methoxycarbonyl-4-hydroxynaphthalene and1-phenyl-2-methoxycarbonyl-4-hydroxy-6,7-dimethoxynaphthalene (2.8grams) from Step 4 was used and 41 mL of a 1M solution of methylmagnesium chloride in tetrahydrofuran was used. For the cyclization, 100mL of toluene and 100 milligrams of dodecylbenzene sulfonic acid wasused. An NMR spectrum showed the recovered product to have structuresconsistent with a mixture of7,7-dimethyl-2,3-dimethoxy-5-hydroxy-7H-benzo[C]fluorene and7,7-dimethyl-9,10-dimethoxy-5-hydroxy-7H-benzo[C]fluorene. This materialwas not purified further but was used directly in the next step as asolution in toluene.

Step 6

The process of Example 1, Step 6 was followed except that the productmixture of the preceding Step 5 and 2.1 grams of1,1-di(4-methoxyphenyl)-2-propyn-1-ol was used. The two resultingproducts were separated by chromatography on silica gel using a 3:1mixture of hexane and ethyl acetate as the elutant. Concentration of therespective fractions followed by recrystallization from ethanol (95%)yielded 336 milligrams of a first product having a melting point of225-228° C. and 192 milligrams of a second product having a meltingpoint of 160-162° C. NMR spectra showed the first (desired) product tohave a structure consistent with the desired product,3,3-di(4-methoxyphenyl)-6,7-dimethoxy-13,13-dimethyl-3H-13H-indeno[2,1-f]naphtho[1,2-b]pyranand the second product to have a structure consistent with3,3-di(4-methoxyphenyl)-10,11-dimethoxy-13,13-dimethyl-3H,13H-indeno[2,1-f]naphtho[1,2-b]pyran.

EXAMPLE 5

The process of Example 3 was followed except that in Step 1 of Example3, 6.75 grams of the product mixture from Example 4, Step 3(1-(3,4-dimethoxyphenyl)-2-methoxycarbonyl-4-acetoxynaphthalene and1-phenyl-2-methoxycarbonyl-4-acetoxy-6,7-dimethoxynaphthalene) was used.In Step 2 of Example 3, 500 milligrams of dodecylbenzene sulfonic acidand 150 mL of xylene (instead of toluene) were used. A mixture ofindanones, 2.8 grams as a red solid, was collected by vacuum filtration.As in Step 4 of Example 3, the crude mixture of isomers from Step 3 (2.7grams) and 6.6 mL of ethyl magnesium chloride as a 2M solution intetrohydrofuran was used. The crude product was purified bychromatography on silica gel using a 2:1 mixture of hexane and ethylacetate as the elutant, yielding 172 milligrams of a first producthaving a melting point range of 220-222° C. and 371 milligrams of asecond product having a melting point of 154-157° C. An NMR spectrumshowed the first (desired) product to have a structure consistent with3,3-di(4-methoxyphenyl)-6,7-dimethoxy-13-hydroxy-13-ethyl-3H-13H-indeno[2,1-f]naphtho[1,2-b]pyran.An NMR spectra showed that the second recovered product had a structureconsistent with3,3-di(4-methoxyphenyl)-10,11-dimethoxy-13-hydroxy-13-ethyl-3H,13H-indeno[2,1-f]naphtho[1,2-b]pyran.The second product was isolated and used as Comparative Example 3described hereinafter.

EXAMPLE 6

The process of Example 1 was followed except that in step 5 of Example1, the reaction flask was charged with1-(3,4-dimethoxyphenyl)-2-methoxycarbonyl-4-hydroxy-6,7-dimethoxynaphthalene(2.5 grams) under a nitrogen atmosphere and 15 mL of anhydroustetrahydrofuran was added to the flask. The reaction mixture was cooledin an ice bath and 15 mL of ethyl magnesium chloride (2M intetrahydrofuran) was added dropwise over 30 minutes. The resultingyellow reaction mixture was stirred at 0° C. for 1 hour, and anadditional 10 ML of ethyl magnesium chloride added. The reaction mixturewas slowly warmed to room temperature and stirred overnight. Thereaction mixture was cooled to 0° C., an additional 10 mL of ethylmagnesium chloride added, and the reaction mixture stirred at roomtemperature for 24 hours. The reaction mixture was carefully poured intoa beaker containing 50 mL of an ice/water mixture. Ether (20 mL) wasadded and the layers separated. The aqueous layer was extracted withfour 50 mL portions of ether. The organic extracts were combined andwashed with 40 mL of water. The organic layer was dried over anhydrousmagnesium sulfate and then concentrated by rotary evaporation. Theresulting yellow oil (1.9 grams) was transferred into a reaction vessel(fitted with a Dean-Stark trap) containing 30 mL of toluene to which twodrops of dodecylbenzene sulfonic acid were added. The reaction mixturewas heated to reflux for 2 hours, cooled, and the toluene solventremoved by rotary evaporation. The resulting dark brown solid waschromatographed on silica gel using a 1:1 hexane/ethyl acetate mixtureas the elutant to provide 506 milligrams of a major product. An NMRspectrum showed the product to have a structure consistent with7,7-diethyl-5-hydroxy-2,3,9,10-tetramethoxy-7H-benzo[C]fluorene.

Step 2

7,7-Diethyl-5-hydroxy-2,3,9,10-tetramethoxy-7H-benzo[C]-fluorene fromStep 1 (200 milligrams), 4,4′-dimethoxyphenyl propargyl alcohol (250milligrams), two drops of dodecylbenzene sulfonic acid and 20 mL ofchloroform were combined in a reaction vessel and stirred at ambienttemperature for 18 hours. The reaction mixture was concentrated byrotary evaporation and the residue was chromatographed on silica gelusing a 1:1 mixture of hexane:ethyl acetate as the elutant. Photochromicfractions were collected, concentrated by rotary evaporation and theresulting solid recrystallized from ethanol (95%) yielding 107 mg ofneedles having a melting point range of 178-181° C. An NMR spectrumshowed the product to have a structure consistent with3,3-di(4-methoxyphenyl)-6,7,10,11-tetramethoxy-13,13-diethyl-3H,13H-indeno[2,1-f]naphtho[1,2-b]pyran.

EXAMPLE 7 Step 1

Sodium methoxide (6.65 grams) was weighed into a dry reaction flaskunder a nitrogen atmosphere. Methanol (200 mL) was added. A solution of3,4-dimethoxybenzaldehyde (19 grams) and 3-benzoyl methyl propionate(21.5 grams) in 200 mL of methanol was added dropwise to the reactionmixture via syringe, with stirring. Stirring was continued at ambienttemperature, overnight. Methanol was removed from the reaction mixtureby rotary evaporation. The residual oil was dissolved in 0.5 L of waterand the resulting basic solution was extracted with hexanes (200 mL).The aqueous layer was acidified with concentrated hydrochloric acid to apH of less than 2 and extracted three times, with 200 mL portions ofethyl ether. The organic layers were combined, washed with brine (200mL) and dried over anhydrous sodium sulfate. Removal of the solvent byrotary evaporation yielded 36.5 grams of a light yellow oil containing3-benzoyl-4-(3,4-dimethoxyphenyl)-3-butenoic acid which was useddirectly in the next step.

Step 2

3-Benzoyl-4-(3,4-dimethoxyphenyl)-3-butenoic acid (15 grams) from Step 1was placed in a reaction flask and 150 mL of acetic anhydride was added.The reaction mixture was heated and maintained at 125° C. overnight.Acetic anhydride was then removed under vacuum, and the residual darksolid was recrystallized from ethyl acetate to yield 6.6 grams of alight yellow solid. The NMR spectrum showed a single product that had astructure consistent with 1-acetoxy-3-benzoyl-6,7-dimethoxynaphthalene.The mother liquid from recrystallization was purified by columnchromatography using a mixture of hexanes/ethyl acetate/methylenechloride in a volume ratio of 5/1/4 as the eluent to yield an additional7.4 grams of the product.

Step 3

1-Acetoxy-3-benzoyl-6,7-dimethoxynaphthalene (6.6 grams) from Step 2 wasadded to a reaction flask containing a mixture of 100 mL of methanol and20 mL of 37% aqueous hydrochloric acid. The reaction mixture was heatedto 70° C. and stirred for 1.5 hours. Methanol was removed by rotaryevaporation, and the residual mixture was dissolved in ethyl ether. Theorganic layer was separated. The aqueous layer was saturated with sodiumchloride and extracted with ethyl acetate. The combined organic phaseswere washed with brine and dried over anhydrous magnesium sulfate. Thesolvents were removed to yield 4.75 grams of a yellow solid,3-benzoyl-6,7-dimethoxy-1-naphthol.

Step 4

3-Benzoyl-6,7-dimethoxy-1-naphthol (2.5 grams) from Step 3 was added toa flask containing 80 mL of anhydrous tetrahydrofuran with stirringunder a nitrogen atmosphere and cooled to −78° C. Phenyl lithium (14 mLof 1.8 M solution in cyclohexane/ether, 70/30) was added dropwise to thereaction mixture over a 10 minute period. The reaction mixture was leftto warm to room temperature overnight. It was then quenched with water,acidified with 2N aqueous hydrochloric acid to a pH less than 3, andextracted with ethyl ether. The organic phase was washed with brine anddried over anhydrous sodium sulfate. The solvents were partially removedby rotary evaporation to give an oil which was triturated with methylenechloride to yield 2.5 grams of a light yellow solid,6,7-dimethoxy-3-diphenylhydroxymethyl-1-naphthol.

Step 5

6,7-Dimethoxy-3-diphenylhydroxymethyl-1-naphthol (1.0 grams) from Step 4was weighed into a reaction flask under a nitrogen atmosphere, 85%phosphoric acid (15 mL) was added with vigorous stirring. The reactionmixture was heated to 95-100° C. After 3 hours, the reaction mixture wascooled to room temperature and poured into 250 mL of water and stirredvigorously for 10 minutes. A white solid precipitated out of the aqueoussolution. The solid was filtered and washed with copious amounts ofwater, and dried under vacuum to get 0.9 grams of product. An NMRspectrum showed the product to have a structure consistent with2,3-dimethoxy-5-hydroxy-7H-7-phenyl-benzo[C]-fluorene. This material wasnot purified further but was used directly in the next step.

Step 6

2,3-dimethoxy-5-hydroxy-7H-7-phenyl-benzo[C]-fluorene from Step 5 (0.40grams), 1,1-di(4-methoxyphenyl-2-propyn-1-ol (0.32 grams),dodecylbenzene sulfonic acid (about 10 milligrams), and 40 mL of toluenewere combined in a reaction vessel and stirred at ambient temperaturefor 2 hours. The solvent was removed by rotary evaporation. Theresulting brown-black solid was purified by column chromatographyyielding 0.55 grams of product having a melting point of 174° C. NMRanalysis showed the product to have a structure consistent with3,3-di(4-methoxyphenyl)-6,7-dimethoxy-13-phenyl-3H,13H-indeno[2,1-f]naphtho[1,2-b]pyran.

EXAMPLE 8

The process of Step 6, Example 7 was followed except that 0.5 milligramsof 2,3-dimethoxy-5-hydroxy-7H-7-phenyl-benzo[C]-fluorene and about 20milligrams of dodecylbenzene sulfonic acid were used. Also,1-(4-methoxyphenyl)-1-(4-morpholinophenyl)-2-propyn-1-ol (0.44 grams)was used instead of 1,1-di(4-methoxyphenyl)-2-propyn-1-ol and methylenechloride (40 mL) was used instead of toluene. The reactants werecombined in a reaction vessel and stirred at ambient temperature for 4hours. The solvent was removed by rotary evaporation. The resultingbrown-black solid was purified by column chromatography yielding 0.70grams having a melting point of 178° C. NMR analysis showed the productto have a structure consistent with3-(4-methoxyphenyl)-3-(4-morpholinophenyl)-6,7-dimethoxy-13-phenyl-3H,13H-indeno[2,1-f]naphtho[1,2-b]pyran.

EXAMPLE 9 Step 1

1-Phenyl-2-methoxycarbonyl-4-hydroxy-6,7-dimethoxynaphthalene (5.0grams) from Step 4 of Example 4 was weighed into a reaction flask undera nitrogen atmosphere and 150 mL of anhydrous tetrahydrofuran (THF) wasadded. Methyl magnesium chloride (25 ml of 3.0 M in THF) was added tothe reaction mixture over a 15 minute period. The reaction mixture wasstirred overnight and then poured into 400 mL of water. The pH of theresulting solution was adjusted to a pH of about 5 with 10 weightpercent aqueous hydrochloric acid. Extraction was carried out withchloroform (three times with 200 mL). The organic layers were combined,washed with saturated aqueous NaCl solution (300 mL) and dried overanhydrous sodium sulfate. Removal of the solvent by rotary evaporationyielded 5.2 grams of a light brown solid. An NMR spectrum showed theproduct to have a structure consistent with1-phenyl-2-(dimethylhydroxymethyl)-4-hydroxy-6,7-dimethoxynaphthalene.This material was not purified further but was used directly in the nextstep.

Step 2

The product from step 1(1-phenyl-2-(dimethylhydroxymethyl)-4-hydroxy-6,7-dimethoxynaphthalene,(5.1 grams) was placed in a reaction flask equipped with a Dean-Starktrap and 150 mL of toluene was added. The reaction mixture was stirredunder a nitrogen atmosphere and dodecylbenzene sulfonic acid (about 50milligrams) was added. The reaction mixture was heated at refluxtemperatures for 2 hours and cooled to room temperature. Removal of thesolvent was done by rotary evaporation to get 5.0 grams of a dark oilysolid that foamed upon drying under vacuum. An NMR spectrum showed theproduct to have a structure consistent with2,3-dimethoxy-5-hydroxy-7,7-dimethyl-7[H)benzo[C]-fluorene. Thismaterial was not purified further but was used directly in the nextstep.

Step 3

The process of Step 6, Example 7 was followed except that 2.5 grams of2,3-dimethoxy-5-hydroxy-7,7-dimethyl-7[H]benzo[C]-fluorene, about 40milligrams of dodecylbenzene sulfonic acid, and 75 mL of toluene wereused. Also, 1-(4-methoxyphenyl)-1-(4-morpholinophenyl)-2-propyn-1-ol(2.5 grams) was used instead of 1,1-di(4-methoxyphenyl)-2-propyn-1-ol.The reactants were combined in a reaction vessel and stirred at ambienttemperature for 3 hours. The solvent was removed by rotary evaporation.The resulting brown-black solid was purified by column chromatography,and subsequently, recrystallized from methanol yielding 3.5 grams ofproduct having a melting point of 168° C. NMR analysis showed theproduct to have a structure consistent with3-(4-methoxyphenyl)-3-(4-morpholinophenyl)-6,7-dimethoxy-13,13-dimethyl-3H,13H-indeno[2,1-f]naphtho[1,2-b]pyran.

EXAMPLE 10

The process of Step 6, Example 7 was followed except that 0.8 grams of2,3-dimethoxy-5-hydroxy-7,7-dimethyl-7[H]benzo[C]-fluorene, about 20milligrams of dodecylbenzene sulfonic acid and 75 mL each of chloroformand toluene were used. Also,1-(4-methoxyphenyl)-1-(4-dimethylaminophenyl)-2-propyn-1-ol (0.7 grams)was used instead of 1,1-di(4-methoxyphenyl)-2-propyn-1-ol. The reactantswere combined in a reaction vessel and stirred at ambient temperaturefor two and a half hours. The solvent was removed by rotary evaporation.The resulting brown-black solid was purified by recrystallization frommethanol yielding 1.1 grams of product having a melting point of 198° C.NMR analysis showed the product to have a structure consistent with3-(4-methoxyphenyl)-3-(4-dimethylaminophenyl)-6,7-dimethoxy-13,13-dimethyl-3H,13H-indeno[2,1-f]naphtho[1,2-b]pyran.

EXAMPLE 11 Step 1

Sodium methoxide (15.2 grams) was weighed into a dry reaction flask.Methanol (100 mL) was added and a nitrogen atmosphere was established. Amixture of 2,3,4-trimethoxybenzaldehyde (50 grams) and 3-benzoyl methylpropionate (50 grams) in 150 mL of methanol was added to the reactionmixture with stirring over a 90 minute period. After stirring anadditional 2 hours, the reaction mixture was poured into 600 mL ofwater. The reaction mixture was extracted with 250 mL of ether fourtimes. The pH of the aqueous layer was adjusted to about 5 withconcentrated hydrochloric acid. A yellowish oil was obtained. It wasextracted three times with 200 mL portions of methylene chloride. Theorganic layers were combined, washed with saturated aqueous NaClsolution (300 mL) and dried over anhydrous sodium sulfate. Removal ofthe solvent by rotary evaporation yielded 90 grams of a light yellowoil. A nuclear magnetic resonance (NMR) spectrum showed the product tohave a structure consistent with3-benzoyl-4-(2,3,4-trimethoxyphenyl)-3-butenoic acid. This material wasnot purified further but was used directly in the next step.

Step 2

3-Benzoyl-4-(2,3,4-trimethoxyphenyl)-3-butenoic acid (47 grams) fromStep 1 was placed in a reaction flask and 200 mL of acetic anhydride and8.4 grams of sodium acetate were added. The reaction mixture was heatedto reflux temperatures for 2 hours and cooled to room temperature. Thesolvent (acetic anhydride) was removed by rotary evaporation. Theresulting residue was dissolved in 400 mL of methylene chloride and 400mL of water was added. Solid sodium carbonate was added to the biphasicmixture until bubbling ceased. The layers separated and the aqueouslayer was extracted with two 100 mL portions of methylene chloride. Theorganic layers were combined, washed with saturated NaCl solution (300mL) and dried over anhydrous sodium sulfate. The solvent (methylenechloride) was removed by rotary evaporation to yield a red oil. An NMRspectrum showed the product to have a structure consistent with2-benzoyl-4-acetoxy-6,7,8-trimethoxynaphthalene. This material was notpurified further but was used directly in the next step.

Step 3

2-Benzoyl-4-acetoxy-6,7,8-trimethoxynaphthalene (45 grams) from Step 2and 250 mL of methanol were combined in a reaction flask. A mixture of100 grams of 50 weight percent aqueous NaOH solution and 200 mL of waterwere added to the reaction flask and the resulting mixture was heated toreflux for 2 hours. The reaction mixture was cooled and then poured into500 mL of water. The pH of the aqueous layer was adjusted to a pH ofabout 5 with concentrated hydrochloric acid. Extraction was done withthree 300 mL portions of chloroform. The organic layers were combined,washed with saturated NaCl solution (300 mL) and dried over anhydroussodium sulfate. The solvent (chloroform) was removed by rotaryevaporation to yield a brownish-red oily solid. An NMR spectrum showedthe product to have a structure consistent with2-benzoyl-4-hydroxy-6,7,8-trimethoxynaphthalene. This material was notpurified further but was used directly in the next step.

Step 4

2-Benzoyl-4-hydroxy-6,7,8-trimethoxynaphthalene (9.9 grams) from Step 3was added to a reaction flask containing 100 mL of anhydroustetrahydrofuran and stirred under a nitrogen atmosphere at roomtemperature. Phenyl lithium (50 mL of a 1.8 M ether solution) was addeddropwise to the reaction mixture with stirring over a 30 minute period.After stirring for an additional 2 hours at ambient temperature, thereaction mixture was poured into 500 mL of water. The pH of the aqueouslayer was adjusted to a pH of about 5 with concentrated hydrochloricacid. Extraction was done with three 200 mL portions of ethyl acetate.The organic layers were combined, washed with saturated NaCl solution(300 mL) and dried over anhydrous sodium sulfate. The solvent (ethylacetate) was removed by rotary evaporation to yield 12.0 grams of abrownish oil. An NMR spectrum showed the product to have a structureconsistent with2-(diphenylhydroxymethyl)-4-hydroxy-6,7,8-trimethoxy-naphthalene. Thismaterial was not purified further but was used directly in the nextstep.

Step 5

2-(Diphenylhydroxymethyl)-4-hydroxy-6,7,8-trimethoxy-naphthalene (10.0grams) from Step 4 was weighed into a reaction flask under a nitrogenatmosphere and 80 mL of 85% phosphoric acid was added accompanied byvigorous stirring. The reaction mixture was heated to 110-120° C. After2 hours, the reaction mixture was cooled to room temperature and pouredinto 250 mL of water and stirred vigorously for 10 minutes. A gray oilysolid precipitated out of the aqueous solution. Extraction was done withthree 200 mL portions of chloroform. The organic layers were combined,washed with a saturated aqueous sodium bicarbonate solution (300 mL),saturated NaCl solution (300 mL), and dried over anhydrous sodiumsulfate. The solvent (chloroform) was removed by rotary evaporation toyield a gray oily solid. A nuclear magnetic resonance (NMR) spectrumshowed the product to have a structure consistent with1,2,3-trimethoxy-5-hydroxy-7H-7-phenyl-benzo[C]-fluorene. This materialwas not purified further but was used directly in the next step.

Step 6

1,2,3-Trimethoxy-5-hydroxy-7,7-dimethyl-7[H]benzo[C]-fluorene (1.75grams) from Step 5, 1.2 grams of 1,1-di(4-methoxyphenyl-2-propyn-1-ol,dodecylbenzene sulfonic acid (about 20 milligrams), and 125 mL ofmethylene chloride were combined in a reaction vessel and stirred atambient temperature overnight. The solvent was removed by rotaryevaporation. The resulting dark solid was purified by columnchromatography, and subsequently, recrystallized from methanol yielding0.84 gram of product having a melting point of 192° C. NMR analysisshowed the product to have a structure consistent with3,3-di(4-methoxyphenyl)-6,7,8-trimethoxy-13-phenyl-3H,13H-indeno[2,1-f]naphtho[1,2-b]pyran.

EXAMPLE 12

The process of Example 3 was followed except for the following: in Step3,3,3-di-(4-methoxyphenyl)-6,7,10,11-tetramethoxy-13-oxo-3H,13H-indeno[2,1-f]naphtho[1,2-b]pyran(1 gram), 3-(4-methoxy)-3-(4-morpholino)-2-propyn-1-ol (1.3 grams) and80 mL of chloroform were used; in Step 4,3-(4-methoxy)-3-(4-morpholino)-6,7,10,11-tetramethoxy-13-oxo-3H,13H-indeno[2,1-f]naphtho[1,2-b]pyran(1 gram), and ethyl magnesium chloride (10 mL of a 2M solution), and 25mL of THF were used. The resulting product was chromatographed on silicagel using 2:1 hexanes/ethyl acetate eluent followed by recrystallizationfrom methanol to provide 608 mg of a product having a melting point of182-184° C. An NMR spectrum showed the product to have a structureconsistent with3-(4-methoxyphenyl)-3-(4-morpholinophenyl)-6,7,10,11-tetramethoxy-13-hydroxy-13-ethyl-3H,13H-indeno[2,1-f]naphtho[1,2-b]pyran.

EXAMPLE 13

The process of Example 3 was used except for the following: in Step 3,3,3-di-(4-methoxyphenyl)-6,7,10,11-tetramethoxy-13-oxo-3H,13H-indeno[2,1-f]naphtho[1,-b]pyran(6.43 grams), 3-(4-methoxy)-3-(4-morpholino)-2-propyn-1-ol (3.9 grams)and 200 mL of chloroform were used; in Step 4,3-(4-methoxy)-3-(4-morpholino)-6,7,10,11-tetramethoxy-13-oxo-3H,13H-indeno[2,1-f]naphtho[1,2-b]pyran(3 grams), butyllithium (5.2 mL of a 1.4 M solution in THF), and 100 mLof THF were used. The resulting product was chromatographed on silicagel using 1:1 hexanes/ethylacetate eluent followed by recrystallizationfrom acetonitrile to provide 708 mg of a product having a melting pointof 251-252° C. An NMR spectrum showed the product to have a structureconsistent with3-(4-methoxyphenyl)-3-(4-morpholinophenyl)-6,7,10,11-tetramethoxy-13-hydroxy-13-butyl-3H,13H-indeno[2,1-f]naphtho[1,2-b]pyran.

EXAMPLE 14 Step 1

The process of Step 1, Example 4 was followed except that 292 grams of1,2-dimethoxy benzene, 297 grams of benzoyl chloride, and 281 grams ofaluminum chloride were used to yield 490 grams of 3,4-dimethoxybenzophenone.

Step 2

The process of Step 2, Example 4 was followed except that 490 grams of3,4-dimethoxybenzophenone and 354 grams of dimethyl succinate weredissolved in toluene (2500 mL) at ˜45° C., and 248 grams ofpotassium-t-butoxide was added portionwise maintaining the temperatureat ˜45° C. After stirring for 12 hours, the mixture was poured into 5000mL of water and vigorously agitated for 20 minutes. The aqueous andorganic phases were separated and the organic phase was extracted with500 mL portions of water two times. The combined aqueous fractions wereacidified to pH 2 with 6N hydrochloric acid and 1000 mL of toluene wasadded. The mixture was agitated, and the toluene layer separated. Thetoluene extract was concentrated by rotary evaporation to yield 500grams of an oil. An NMR spectrum showed the product to have structuresconsistent with a mixture of (E and Z)4-(3,4-dimethoxyphenyl)-4-phenyl-3-methoxycarbonyl-3-butenoic acids, butstrongly enriched in the E isomer.

Step 3

The oil isolated from Step 2 was heated to reflux in 2.1 L of aceticanhydride under a nitrogen atmosphere. The reaction mixture was cooledand the acetic anhydride was removed by rotary evaporation to yield athick gum, which solidified upon standing. The solid was dissolved inboiling methanol (3 L) and allowed to cool overnight. The crystals thatformed were collected by vacuum filtration, washed with methanol andthen air-dried. An NMR spectrum showed the crystals (249 grams) to havea structure consistent with1-phenyl-2-methoxycarbonyl-4-acetoxy-6,7-dimethoxynaphthalene. Theisomer 1-(3,4-dimethoxyphenyl)-2-methoxycarbonyl-4-acetoxynaphthaleneremained in the filtrate as a mixture with1-phenyl-2-methoxycarbonyl-4-acetoxy-6,7-dimethoxynaphthalene.

Step 4

1-Phenyl-2-methoxycarbonyl-4-acetoxy-6,7-dimethoxynaphthalene (66.4grams) from Step 3, 500 mL of a 10 weight percent aqueous sodiumhydroxide solution and 50 mL of methanol were added to a reaction flaskand heated to reflux for 3 hours and then cooled to room temperature.The reaction mixture was poured onto an aqueous solution of 4Nhydrochloric acid/ice mixture (˜400 mL). A white precipitate formed andwas collected by vacuum filtration, washed with water and was air-dried.Recrystallization from ethanol (95 weight percent) gave 57 grams of1-phenyl-4-hydroxy-6,7-dimethoxy-2-naphthoic acid.

Step 5

1-Phenyl-4-hydroxy-6,7-dimethoxy-2-naphthoic acid, (55 grams) from Step4, and dodecylbenzenesulfonic acid (1 gram) were added to a reactionflask containing 1 liter of xylene and heated to reflux for 36 hours.The reaction was cooled and the resulting red precipitate was collectedby vacuum filtration and washed with toluene. The red solid wasair-dried yielding 48.1 grams of product. An NMR spectrum showed theproduct to have a structure consistent with2,3-dimethoxy-5-hydroxy-7H-benzo[C]fluoren-7-one.

Step 6

The process of Example 3, Step 3 was followed except2,3-dimethoxy-5-hydroxy-7H-benzo[C]fluoren-7-one (13.5 grams) from Step5 above was used instead of2,3,9,10-tetramethoxy-5-hydroxy-7H-benzo[C]fluoren-7-one and 8 grams of1-(4-morpholinophenyl)-1-phenyl-2-propyn-1-ol was used in place of1,1-di(4-methoxyphenyl)-2-propyn-1-ol, and 250 mL of chloroform wereused. Red needles (5 grams) having an NMR spectrum consistent with3-(4-morpholinophenyl)-3-phenyl-6,7-dimethoxy-13-oxo-3H,13H-indeno[2,1-f]naphtho[1,2-b]pyranwere isolated by filtration from a few mL of cold acetone.

Step 7

3-(4-morpholinophenyl)-3-phenyl-6,7-dimethoxy-13-oxo-3H,13H-indeno[2,1-f]naphtho[1,2-b]pyran(5 grams)from Step 6 was added to a reaction flask containing THF (100mL). Under a nitrogen atmosphere at 0° C., an excess of ethyl magnesiumchloride (20 mL of a 2 M solution in THF) was added to the reactionflask. The resulting reaction was stirred at 0° C. for 30 minutes andthen warmed to room temperature. The reaction mixture was poured onto200 mL of ice water then acidified to pH 3 with an aqueous 2Nhydrochloric acid solution. Diethylether (100 mL) was added and theorganic phase separated. The solvents were removed by rotary evaporationand the resulting oil was chromatographed on a silica column usinghexane:ethyl acetate (2:1) as eluant. The photochromic fractions wereconcentrated and the residue crystallized from methanol to give 2 gramsof a white solid (m.p. 208-209° C.) An NMR spectrum showed the productto have a structure consistent with3-(4-morpholinophenyl)-3-phenyl-6,7-dimethoxy-13-hydroxy-13-ethyl-3H,13H-indeno[2,1,-f]naphtho[1,2-b]pyran.

EXAMPLE 15

The procedure for Example 14 was followed except that in Step 61-di(4-methoxyphenyl)-2-propyn-1-ol was used in place of1-(4-morpholino-phenyl)-1-phenyl-2-propyn-1-ol. The resulting purplecrystals (14.5 grams) had an NMR spectrum showing the product to have astructure consistent with3,3-di(4-methoxyphenyl)-6,7-dimethoxy-13-oxo-3H,13H-indeno[2,1-f]naphtho[1,2-b]pyran.In Step 7, 1.8 grams of3,3-di(4-methoxyphenyl)-6,7-dimethoxy-13-oxo-3H,13H-indeno[2,1-f]naphtho[1,2-b]pyranin 30 mL of THF was used and n-butyllithium (2.5 mL of a 2.5 M solutionin THF) was used instead of ethyl magnesium chloride. The resulting oilwas chromatographed on silica gel using 3:1 hexanes/ethyl acetate aseluent. Recrystallization from 3:1 hexanes/ethyl acetate provided 518 mgof a beige solid having a melting point of 193-195° C. An NMR spectrumshowed the product to have a structure consistent with3,3-di(4-methoxyphenyl)-6,7-dimethoxy-13-hydroxy-13-butyl-3H,13H-indeno[2,1,-f]naphtho[1,2-b]pyran.

EXAMPLE 16

The procedure for Example 14 was followed except in Step 7,3-(4-morpholino)-3-phenyl-(6,7-dimethoxy-13-oxo-3H,13H-indeno[2,1-f]naphtho[1,2-b]pyran(1.0 gram) and n-butyllithium (1.36 mL of a 2.5 M solution in THF) wasused in place of ethyl magnesium chloride. The resulting oil waschromatographed on silica gel using 2:1 hexanes/ethyl acetate as theeluent. Recrystallization from methylene chloride/ethanol (95%) provideda beige powder (310 mg) which had a melting point of 230-231° C. An NMRspectrum showed the product to have a structure consistent with3-(4-morpholinophenyl)-3-phenyl-6,7-dimethoxy-13-hydroxy-13-butyl-3H,13H-indeno[2,1,-f]naphtho[1,2-b]pyran.

EXAMPLE 17 Step 1

2,3-Dimethoxy-5-hydroxy-7H-benzo[C]-fluoren-7-one (3.0 grams, 9.8 mmol)from Step 5, Example 14 was added to a reaction flask containing 400 mLof chloroform. A catalytic amount of p-dodecylbenzene sulfonic acid(about 50 mg) was added to a reaction flask followed by the addition of1-(4-methoxyphenyl)-1-(4-morpholinophenyl)-2-propyn-1-ol (1.3 grams).The reaction mixture was stirred at ambient temperature overnight. Anadditional portion of1-(4-methoxyphenyl)-1-(4-morpholinophenyl)-2-propyn-1-ol (0.97 grams)was added and the stirring was continued for 8 hours. The unreacted6,7-dimethoxy-5-hydroxy-7H-benzo[C]-fluoren-7-one (2.1 grams, 6.7 mmol)was removed by filtration. The filtrate was stripped off the solvent andtriturated with acetone to yield 1.88 grams of a red solid thatdisplayed photochromism in solution. The product,6,7-dimethoxy-3-(4-methoxyphenyl)-3-(4-morpholinophenyl)-13-oxo-3H,13H-indeno[2,1-f]naphtho[1,2-b]pyran,was taken on to the next step without further purification.

Step 2

6,7-Dimethoxy-3-(4-methoxyphenyl)-3-(4-morpholinophenyl)-13-oxo-3H,13H-indeno[2,1-f]naphtho[1,2-b]pyranfrom Step 1 (1.88 grams) was added to a dry reaction flask under anitrogen atmosphere. Anhydrous tetrahydrofuran (75 mL) was added and thereaction mixture was stirred to form a red suspension. Ethyl magnesiumchloride (4 mL of a 2 M solution in tetrahydrofuran) was added dropwise,with stirring, at ambient temperature. Upon completion of ethylmagnesium chloride addition, the red suspension became a brown solution.The reaction mixture was stirred for an additional 40 minutes andquenched with water (100 mL). The organic phase was separated, theaqueous phase was neutralized with 2N hydrochloric acid to a pH of 7.The aqueous phase was extracted three times with 50 mL portions of ethylether. All of the organic phases were combined and dried over anhydroussodium sulfate. The solvents were removed by rotary evaporation. Theresulting oily substance was recrystallized from ethyl acetate to yield0.93 g of a light solid having a melting point of 156-157° C. The NMRspectra showed the product to have a structure consistent with6,7-dimethoxy-3-(4-methoxyphenyl)-3-(4-morpholinophenyl)-13-hydroxy-13-ethyl-3H,13H-indeno[2,1-f]naphtho[1,2-b]pyran.

EXAMPLE 18

6,7-Dimethoxy-3-(4-methoxyphenyl)-3-(4-morpholinophenyl)-13-hydroxy-13-ethyl-3H,13H-indeno[2,1-f]naphtho[1,2-b]pyran(0.6 gram) from Step 2 of Example 17 was added to a reaction flaskcontaining 50 mL of methanol. Concentrated (37%) hydrochloric acid (10mL) was slowly added to the suspension and formation of a solution wasobserved. The solution was left to stir overnight at ambienttemperature. Potassium hydroxide in methanol was added until a neutralpH was obtained. The solvent was removed under vacuum. The resultingsolid was separated by filtration. The aqueous filtrate was extractedwith ethyl acetate. The ethyl acetate was removed under vacuum and theorganic solids were combined and purified by column chromatography usinga mixture of acetone/hexanes in a volume ratio of 40/60 as the eluent.The collected photochromic fractions were further purified byrecrystallization from methanol to yield 0.11 grams of a white solidhaving a melting point of 175-176° C. The NMR spectra showed the productto have a structure consistent with3-(4-methoxyphenyl)-3-(4-morpholinophenyl)-6,7-dimethoxy-13-ethyl-13-methoxy-3H,13H-indeno[2,1-f]naphtho[1,2-b]pyran.

EXAMPLE 19

6,7-Dimethoxy-3-(4-methoxyphenyl)-3-(4-morpholinophenyl)-13-oxo-3H,13H-indeno[2,1-f]naphtho[1,2-b]pyran(1.55 grams) from Step 1 of Example 17 was added to a dry reaction flaskunder a nitrogen atmosphere. Anhydrous tetrahydrofuran (250 mL) wasadded and the reaction mixture was stirred to form a red suspension.Methyl lithium (2.3 mL of a 1.4 M solution in ethyl ether) was addeddropwise, with stirring, at ambient temperature. Upon completion of themethyl lithium addition, the red suspension became a brown coloredsolution. The reaction mixture was stirred an additional 40 minutes andquenched with water (100 mL) and then the pH was adjusted with 2Nhydrochloric acid to a pH of 6. The reaction mixture was extracted threetimes with 100 mL portions of ethyl ether, the organic phases werecombined and dried over anhydrous sodium sulfate. The solvents wereremoved by rotary evaporation. The residue was recrystallized frommethanol to yield 0.95 g of light solid with the melting point of199-200° C. The product decomposed at this temperature. The NMR spectrashowed the product to have a structure consistent with3-(4-methoxyphenyl)-3-(4-morpholinophenyl)-6,7-dimethoxy-13-hydroxy-13-methyl-3H,13H-indeno[2,1-f]naphtho[1,2-b]pyran.

EXAMPLE 20

The process of Example 18 was followed except that6,7-dimethoxy-3-(4-methoxyphenyl)-3-(4-morpholinophenyl)-13-hydroxy-13-methyl-3H,13H-indeno[2,1-f]naphtho[1,2-b]pyran(0.2 grams) was used instead of3-(4-methoxyphenyl)-3-(4-morpholinophenyl)-6,7-dimethoxy-13-hydroxy-13-ethyl-3H,13H-indeno[2,1-f]naphtho[1,2-b]pyran,boiling methanol was added instead of methanol at room temperature, 0.6mL of concentrated hydrochloric acid was used instead of 10 mL, andstirring at ambient temperature continued for 2 days, as opposed toovernight. The resulting light solid (70 milligrams) had a melting pointof 176-177° C. The NMR spectra showed the product to have a structureconsistent with3-(4-methoxyphenyl)-3-(4-morpholinophenyl)-6,7-dimethoxy-13-methoxy-13-methyl-3H,13H-indeno[2,1-f]naphtho[1,2-b]pyran.

COMPARATIVE EXAMPLES 1-3

Three indeno[2,1-f]naphtho[1,2-b]pyrans lacking a substituent on atleast two of the 5-, 6-, 7- and 8-positions were prepared followingsimilar processes to those of Examples 1-6. The compounds of theComparative Examples were determined to be:

(1)3,3-di(4-methoxyphenyl)-13-hydroxy-13-ethyl-3H-13H-indeno[2,1-f]naphtho[1,2-b]pyran;

(2)3,3-di(4-methoxyphenyl)-6,11-dimethoxy-13-hydroxy-13-ethyl-3H-13H-indeno[2,1-f]naphtho[1,2-b]pyran;and

(3)3,3-di(4-methoxyphenyl)-10,11-dimethoxy-13-hydroxy-13-ethyl-3H-13H-indeno[2,1-f]naphtho[1,2-b]pyran.

EXAMPLE 21 Part A

Testing was done with the photochromic compounds described in Examples 1through 20 and Comparative Examples 1 through 3 in the following manner.A quantity of photochromic compound calculated to yield a 1.5×10⁻³ molalsolution was added to a flask containing 50 grams of a monomer blend of4 parts ethoxylated bisphenol A dimethacrylate (BPA 2EO DMA), 1 partpoly(ethylene glycol) 600 dimethacrylate, and 0.033 weight percent2,2′-azobis(2-methyl propionitrile) (AIBN). The photochromic compoundwas dissolved into the monomer blend by stirring and gentle heating, ifnecessary. After a clear solution was obtained, it was poured into aflat sheet mold having the interior dimensions of 2.2 mm×6 inches (15.24cm)×6 inches (15.24 cm). The mold was sealed and placed in a horizontalair flow, programmable oven programmed to increase the temperature from40° C. to 95° C. over a 5 hour interval, hold the temperature at 95° C.for 3 hours, lower it to 60° C. over a 2 hour interval and then hold itat 60° C. for 16 hours. After the mold was opened, the polymer sheet wascut using a diamond blade saw into 2 inch (5.1 centimeters) testsquares.

Part B

The photochromic test squares of Part A were tested for photochromicresponse rates on an optical bench. Prior to testing on the opticalbench, the photochromic test squares were exposed to 365 nanometerultraviolet light for about 15 minutes to activate the photochromiccompounds and then placed into a 76° C. oven for about 15 minutes tobleach the photochromic compounds. The test squares were then cooled toroom temperature, exposed to fluorescent room lighting for at least 2hours and then kept covered for at least 2 hours prior to testing on anoptical bench maintained at 72° F. (22.2° C.). The bench was fitted witha 250 watt Xenon arc lamp, a remote controlled shutter, a copper sulfatebath acting as a heat sink for the arc lamp, a Schott WG-320 nm cut-offfilter which removes short wavelength radiation; neutral densityfilter(s) and a sample holder in which the square to be tested wasinserted. The power output of the optical bench, i.e., the dosage oflight that the sample lens would be exposed to, was calibrated with aphotochromic test square used as a reference standard. This resulted ina power output ranging from 0.15 to 0.20 milliwatts per squarecentimeter (mW/cm2). Measurement of the power output was made using aGRASEBY Optronics Model S-371 portable photometer (Serial #21536) with aUV-A detector (Serial #22411) or comparable equipment. The UV-A detectorwas placed into the sample holder and the light output was measured.Adjustments to the power output were made by increasing or decreasingthe lamp wattage or by adding or removing neutral density filters in thelight path.

A monitoring, collimated beam of light from a tungsten lamp was passedthrough the square at a small angle (approximately 30°) normal to thesquare. After passing through the square, the light from the tungstenlamp was directed to a detector through Spectral Energy Corp. GM-200monochromator set at the previously determined visible lambda max of thephotochromic compound being measured. The output signals from thedetector were processed by a radiometer.

Change in optical density (ΔOD) was determined by inserting a testsquare in the bleached state into the sample holder, adjusting thetransmittance scale to 100%, opening the shutter from the Xenon lamp toprovide ultraviolet radiation to change the test square from thebleached state to an activated (i.e., darkened) state, measuring thetransmittance in the activated state, and calculating the change inoptical density according to the formula: ΔOD=log(100/% Ta), where % Tais the percent transmittance in the activated state and the logarithm isto the base 10.

The optical properties of the photochromic compounds in the test squaresare reported in Table 1. The ΔOD/Min, which represents the sensitivityof the photochromic compound's response to UV light, was measured overthe first five (5) seconds of UV exposure, then expressed on a perminute basis. The saturation optical density (ΔOD@ Saturation) was takenunder identical conditions as the ΔOD/Min, except UV exposure wascontinued for 15 minutes.

The lambda max (Vis) is the wavelength in the visible spectrum at whichthe maximum absorption of the activated (colored) form of thephotochromic compound in a test square occurs. The lambda max (Vis)wavelengths reported in Table 1 were determined by testing thephotochromic test square polymerizates of Part A in a Varian Cary 3uv-visible spectrophotometer. The bleach rate (T 1/2) is the timeinterval in seconds for the absorbance of the activated form of thephotochromic compound in the test squares to read one half the highestabsorbance at room temperature (72° F., 22.2° C.) after removal of thesource of activating light.

Each of the compounds of the Examples and the Comparative Examplesexhibited dual peak absorptions in the visible spectrum (lambda maxvisible) in distinct color regions. For each lambda max visible, thecorresponding optical density (Δ OD/Min and Δ OD at saturation) for thedesired compounds of the Examples and Comparative Examples are tabulatedin Table 1 for the two bands (A and B) of peak absorption for eachcompound. Table 1 also includes the bleach rate (T 1/2) for each of thecompounds as measured at band B. The ratings of the Relative Δ OD atSaturation Test for the bands A and B of each of the Examples andComparative Examples are calculated as follows: Δ OD at saturation (BandA)/Δ OD at saturation (Band B)×100. The ratings of the Relative Δ OD atSaturation Test for each of the compounds is tabulated in Table 2.

TABLE 1 Bleach Compound Sensitivity ΔOD @ Rate λ MAX (nm) ExampleΔOD/MIN Saturation T ½ sec Vis  1 (Band A) 0.33 0.99 445  1 (Band B)0.24 0.79 526 611  2 (Band A) 0.32 1.10 485  2 (Band B) 0.29 1.07 854618  3 (Band A) 0.34 0.62 460  3 (Band B) 0.24 0.41 155 623  4 (Band A)0.39 1.11 455  4 (Band B) 0.22 0.71 267 576  5 (Band A) 0.26 0.42 458  5(Band B) 0.19 0.27  87 584  6 (Band A) 0.46 1.02 440  6 (Band B) 0.370.73 310 608  7 (Band A) 0.17 0.66 460  7 (Band B) 0.16 0.43 206 577  8(Band A) 0.14 0.43 484  8 (Band B) 0.18 0.44 179 603  9 (Band A) 0.180.60 477  9 (Band B) 0.23 0.59 204 597 10 (Band A) 0.20 0.41 500 10(Band B) 0.28 0.50 130 615 11 (Band A) 0.28 0.66 482 11 (Band B) 0.250.62 183 581 12 (Band A) 0.26 0.46 480 12 (Band B) 0.27 0.43 130 632 13(Band A) 0.27 0.39 482 13 (Band B) 0.25 0.37  85 634 14 (Band A) 0.240.41 485 14 (Band B) 0.22 0.40 108 600 15 (Band A) 0.29 0.37 457 15(Band B) 0.18 0.22  76 579 16 (Band A) 0.22 0.37 485 16 (Band B) 0.190.35 113 600 17 (Band A) 0.21 0.25 480 17 (Band B) 0.18 0.24  84 603 18(Band A) 0.21 0.27 483 18 (Band B) 0.18 0.27  86 604 19 (Band A) 0.180.34 481 19 (Band B) 0.22 0.35  98 603 20 (Band A) 0.16 0.34 483 20(Band B) 0.17 0.37 105 604 Comp. Ex. 1 0.21 0.16 437 (B and A) Comp. Ex.1 0.29 0.27  47 562 (B and B) Comp. Ex. 2 0.22 0.36 499 (B and A) Comp.Ex. 2 0.32 0.51 130 607 (B and B) Comp. Ex. 3 0.32 0.34 445 (B and A)Comp. Ex. 3 0.48 0.48  76 600 (B and B)

TABLE 2 Compound Example Relative ΔOD at Saturation  1 125  2 103  3 151 4 156  5 155  6 140  7 153  8 98  9 102 10 82 11 106 12 106 13 105 14103 15 168 16 106 17 104 18 100 19 97 20 92 Comp. Ex. 1 59 Comp. Ex. 270 Comp. Ex. 3 71

The data presented in Tables 1 and 2 show that each tested compound ofthe present invention has two absorption peaks in the visible spectrumand a rating greater than 80 in the Relative ΔOD at Saturation Test.

This data demonstrates that a single compound of the present inventionexhibits a blended activated hue. In the preparation of photochromicarticles with a desired activated hue, a combination of complementaryphotochromic compounds each having an activated visible absorptionmaximum may be used. The activated visible absorption maxima of thevarious compounds are thereby blended to achieve the desired activatedcolor. By employing a compound of the present invention having twoactivated visible absorption maxima, fewer distinct compounds arerequired to achieve a blend of activated visible absorption maxima toproduce the desired activated hue, e.g. neutral color. In addition, theblended activated hue of a compound of the present invention isparticularly suitable for use in photochromic articles having a brownactivated hue due to the greater optical density of band A (420-500 nm)than the optical density of band B (500-650 nm).

The present invention has been described with reference to specificdetails of particular embodiments thereof. It is not intended that suchdetails be regarded as limitations upon the scope of the inventionexcept insofar as to the extent that they are included in theaccompanying claims.

We claim:
 1. A naphthopyran compound of indeno[2,1-f]naphtho[1,2-b]pyranstructure, represented by the following graphic formula I:

wherein, (a) in the 7 position, a group R₅ selected from the groupconsisting of: (i) the group, —OR₈′, wherein R₈′ is phenyl(C₁-C₃)alkyl,C₁-C₆ alkyl, mono(C₁-C₆)alkyl substituted phenyl(C₁-C₃)alkyl,mono(C₁-C₆)alkoxy substituted phenyl(C₁-C₃)alkyl, C₁-C₆alkoxy(C₂-C₄)alkyl, C₃-C₇ cycloalkyl, mono(C₁-C₄)alkyl substituted C₃-C₇cycloalkyl, C₁-C₆ chloroalkyl, C₁-C₆ fluoroalkyl, allyl, or R₈′ is thegroup, —CH(R₉)Q, wherein R₉ is hydrogen or C₁-C₃ alkyl; and (ii) a groupselected from: (1) —N(R₁₅)R₁₆ wherein R₁₅ and R₁₆ are each selected fromthe group consisting of hydrogen, C₁-C₈ alkyl, phenyl, naphthyl, theheteroaromatic groups, furanyl, benzofuran-2-yl, benzofuran-3-yl,thienyl, benzothien-2-yl, benzothien-3-yl, dibenzofuranyl,dibenzothienyl, benzopyridyl and fluorenyl, C₁-C₈ alkylaryl, C₃-C₂₀cycloalkyl, C₄-C₂₀ bicycloalkyl, C₅-C₂₀ tricycloalkyl and C₁-C₂₀alkoxyalkyl, wherein said aryl group is phenyl or naphthyl; (2) anitrogen containing ring represented by the following graphic formula:

 wherein Y is selected from the group consisting of —CH₂—, —CH(R₁₇)—,—C(R₁₇)(R₁₇)—, —CH(aryl)—, —C(aryl)₂—, and —C(R₁₇)(aryl)—, and X isselected from the group consisting of —Y—, —O—, —S—, —(O)—, —S(O₂)—,—NH—, —NR₁₇— and —N-aryl, wherein R₁₇ is C₁-C₆ alkyl, said arylsubstituent is phenyl or naphthyl, m is the integer 1, 2 or 3, and p isthe integer 0, 1, 2, or 3 and when p is O, X is Y; and (3) a grouprepresented by the following graphic formulae:

 wherein R₁₉, R₂₀ and R₂₁ are each hydrogen, C₁-C₅ alkyl, phenyl ornaphthyl, or the groups R₁₉ and R₂₀ together form a ring of 5 to 8carbon atoms and R₁₈ is C₁-C₆ alkyl, C₁-₆ alkoxy, fluoro or chloro; (b)in the 6 position, a group R₆, said group being the same as R₅, definedhereinbefore; or (c) R₅ and R₆ together form the following graphicformula:

 wherein J and K are each oxygen or the group —NR₁₅—; (d) optionally, inthe 8 position, a group R₄, said group being the same as R₅ definedhereinbefore; and (e) in the 3 position, weak to moderate electron donorsubstituents, and optional substituents at the 5-, 8-, 9-, 10-, 11-, 12-or 13-positions provided that said naphthopyran demonstrates a rating ofat least 80 in the Relative ΔOD at Saturation Test.
 2. The naphthopyrancompound of claim 1 wherein, (a) R₁ and R₂ are each selected from thegroup consisting of: (i) hydrogen, hydroxy, C₁-C₆ alkyl, amino, mono- ordi-substituted amino, C₃-C₇ cycloalkyl, allyl, benzyl, mono-substitutedbenzyl, chloro, fluoro, the group, —C(O)W, wherein W is hydroxy, C₁-C₆alkyl, C₁-C₆ alkoxy, phenyl, mono-substituted phenyl, amino,mono(C₁-C₆)alkylamino, di(C₁-C₆)alkylamino, morpholino, piperidino orpyrrolidyl, said amino substituents being selected from the groupconsisting of C₁-C₆ alkyl, phenyl, benzyl and naphthyl, said benzyl andphenyl substituents being C₁-C₆ alkyl or C₁-C₆ alkoxy; (ii) theunsubstituted, mono- di- or trisubstituted groups phenyl, naphthyl,phenanthryl, pyrenyl, quinolyl, isoquinolyl, benzofuranyl, thienyl,benzothienyl, dibenzofuranyl, dibenzothienyl, carbazolyl, indolyl, saidgroup substituents in (a)(ii) being selected from the group consistingof chloro, fluoro, C₁-C₆ alkyl and C₁-C₆ alkoxy; (iii) monosubstitutedphenyl, having a substituent at the para position that is a linkinggroup, —(CH₂)_(t)— or —O—(CH₂)_(t)—, wherein t is the integer 1, 2, 3,4, 5 or 6, connected to an aryl group, which is a member of anotherphotochromic naphthopyran; (iv) the group, —OR₈ wherein R₈ is C₁-C₆alkyl, C₁-C₆ acyl, phenyl(C₁-C₃)alkyl, mono(C₁-C₆)alkyl substitutedphenyl(C₁-C₃)alkyl, mono(C₁-C₆)alkoxy substituted phenyl(C₁-C₃)alkyl,C₁-C₆ alkoxy(C₂-C₄)alkyl, C₃-C₇ cycloalkyl, mono(C₁-C₄)alkyl substitutedC₃-C₇ cycloalkyl, C₁-C₆ chloroalkyl, C₁-C₆ fluoroalkyl, allyl, benzoyl,monosubstituted benzoyl, naphthoyl or monosubstituted naphthoyl, saidbenzoyl and naphthoyl group substituents being C₁-C₆ alkyl or C₁-C₆alkoxy, or R₈ is the group —CH(R₉)Q, wherein R₉ is hydrogen or C₁-C₃alkyl and Q is —CN, —CF₃, or —COOR₁₀, and R₁₀ is hydrogen or C₁-C₃alkyl, or R₈ is the group, —C(O)V, wherein V is hydrogen, C₁-C₆ alkoxy,phenoxy, mono- or di-(C₁-C₆)alkyl substituted phenoxy, mono- ordi-(C₁-C₆)alkoxy substituted phenoxy, the unsubstituted, mono- ordi-substituted aryl groups, phenyl and naphthyl, amino,mono(C₁-C₆)alkylamino, di(C₁-C₆)alkylamino, phenylamino, mono- ordi-(C₁-C₆)alkyl substituted phenylamino, or mono- or di-(C₁-C₆)alkoxysubstituted phenylamino, said aryl group substituents being C₁-C₆ alkylor C₁-C₆ alkoxy; (v) the group —CH(Q′)₂ wherein Q′ is —CN or —COOR₁₁,wherein R₁₁ is hydrogen, C₁-C₆ alkyl, phenyl(C₁-C₃)alkyl,mono(C₁-C₆)alkyl substituted phenyl(C₁-C₃)alkyl, mono(C₁-C₆)alkoxysubstituted phenyl(C₁-C₃)alkyl, or the unsubstituted, mono- ordi-substituted aryl groups phenyl or naphthyl, each of said phenyl andnaphthyl group substituents being C₁-C₆ alkyl or C₁-C₆ alkoxy; (vi) thegroup —CH(R₁₂)G, wherein R₁₂ is hydrogen, C₁-C₆ alkyl or theunsubstituted, mono- or di-substituted aryl groups phenyl and naphthyl,and G is —COOR₁₁, —COR₁₃ or —CH₂OR₁₄, wherein R₁₃ is hydrogen, C₁-C₆alkyl, the unsubstituted, mono- or di-substituted aryl groups phenyl ornaphthyl, amino, mono(C1-C6)alkylamino, di(C₁-C₆)alkylamino,phenylamino, mono- or di-(C₁-C₆)alkyl substituted phenylamino, mono- ordi-(C₁-C₆)alkoxy substituted phenylamino, diphenylamino, mono- ordi(C₁-C₆)alkyl substituted diphenylamino, mono- or di(C₁-C₆)alkoxysubstituted diphenylamino, morpholino, or piperidino, wherein R₁₄ ishydrogen, —C(O)R₁₁, C₁-C₆ alkyl, C₁-C₃ alkoxy(C₁-C₆)alkyl,phenyl(C₁-C₃)alkyl, mono(C₁-C₆)alkoxy substituted phenyl(C₁-C₃)alkyl, orthe unsubstituted, mono- or di-substituted aryl groups phenyl ornaphthyl, each of said phenyl and naphthyl group substituents beingC₁-C₆ alkyl or C₁-C₆ alkoxy; and (vii) the group T represented by theformula: —Z[(OC₂H₄)_(x) (OC₃H₆)_(y) (OC₄H₈)_(z)]Z′ —[(OC₂H₄)_(x)(OC₃H₆)_(y) (OC₄H₈)_(z)]Z′ wherein —Z is —C(O)— or —CH₂—, Z′ is C₁-C₃alkoxy or a polymerizable group, x, y and z are each a number between 0and 50, and the sum of x, y and z is between 2 and 50; or (viii) R₁ andR₂ together form an oxo group, a substituted or unsubstitutedspiro-carbocyclic ring containing 3 to 6 carbon atoms or a substitutedor unsubstituted spiro-heterocyclic group containing 1 or 2 oxygen atomsand 3 to 6 carbon atoms including the spirocarbon atom, saidspiro-carbocyclic ring and spiro-heterocyclic group being annellatedwith 0, 1 or 2 benzene rings, said substituents being hydrogen or C₂-C₆alkyl; (b) each R₃ is the group T, hydrogen, C₁-C₆ alkyl, C₁-C₆ alkoxy,C₃-C₇ cycloalkyl, phenyl, benzyl, di(C₁-C₆)alkylamino dicyclohexylamino,diphenylamino, piperidyl, morpholinyl, pyridyl, bromo, chloro, fluoro,or the group —C(O)W and n is the integer 0, 1, or 2, or when n is 2, andthe R₃ groups are adjacent, the R₃ groups together form a fusedcarbocyclic or a fused heterocyclic ring selected from the groupconsisting of benzo, pyridino, pyrazino, pyrimidino, furano,dihydrofurano and thiopheno, said ring being fused to the n, o or psides of the naphthopyran; (c) R₄ is selected from hydrogen, C₁-C₆alkyl, chloro or fluoro; or R₄, R₅ and R₆ are each selected from thegroup consisting of: (i) the group, —OR₈′, wherein R₈′ isphenyl(C₁-C₃)alkyl, C₁-C₆ alkyl, mono(C₁-C₆)alkyl substitutedphenyl(C₁-C₃)alkyl, mono(C₁-C₆)alkoxy substituted phenyl(C₁-C₃)alkyl,C₁-C₆ alkoxy(C₂-C₄)alkyl, C₃-C₇ cycloalkyl, mono(C₁-C₄)alkyl substitutedC₃-C₇ cycloalkyl, C₁-C₆ chloroalkyl, C₁-C₆ fluoroalkyl, allyl, or R₈′ isthe group, —CH(R₉)Q, wherein R₉ is hydrogen or C₁-C₃ alkyl; and (ii) agroup selected from: (1) —N(R₁₅)R₁₆ wherein R₁₅ and R₁₆ are eachselected from the group consisting of hydrogen, C₁-C₈ alkyl, phenyl,naphthyl, the heteroaromatic groups, furanyl, benzofuran-2-yl,benzofuran-3-yl, thienyl, benzothien-2-yl, benzothien-3-yl,dibenzofuranyl, dibenzothienyl, benzopyridyl and fluorenyl, C₁-C₈alkylaryl, C₃-C₂₀ cycloalkyl, C₄-C₂₀ bicycloalkyl, C₅-C₂₀ tricycloalkyland C₁-C₂₀ alkoxyalkyl, wherein said aryl group is phenyl or naphthyl;(2) a nitrogen containing ring represented by the following graphicformula:

 wherein Y is selected from the group consisting of —CH₂—, —CH(R₁₇)—,—C(R₁₇)(R₁₇)—, —CH(aryl)—, —C(aryl)₂—, and —C(R₁₇)(aryl)—, and X isselected from the group consisting of —Y—, —O—, —S—, —S(O)—, —S(O₂)—,—NH—, —NR₁₇— and —N-aryl, wherein R₁₇ is C₁-C₆ alkyl, said arylsubstituent is phenyl or naphthyl, m is the integer 1, 2 or 3, and p isthe integer 0, 1, 2, or 3 and when p is O, X is Y; and (3) a grouprepresented by the following graphic formulae:

 wherein R₁₉, R₂₀ and R₂₁ are each hydrogen, C₁-C₅ alkyl, phenyl ornaphthyl, or the groups R₁₉ and R₂₀ together form a ring of 5 to 8carbon atoms and R₁₈ is C₁-C₆ alkyl, C₁-₆ alkoxy, fluoro or chloro; or(iii) R₅ and R₆ together form the following graphic formula:

 wherein J and K are each oxygen or the group —NR₁₅—; (d) R₇ is selectedfrom hydrogen, C₁-C₆ alkyl, chloro or fluoro; (e) B and B′ are eachselected from the group consisting of: (i) mono-T-substituted phenyl(ii) the unsubstituted, mono-, di-, and tri-substituted aryl groups,phenyl and naphthyl; (iii) 9-julolidinyl and the unsubstituted, mono-and di-substituted heteroaromatic groups, pyridyl furanyl,benzofuran-2-yl, benzofuran-3-yl, thienyl, benzothien-2-yl,benzothien-3-yl, dibenzofuranyl, dibenzothienyl, carbazoyl,benzopyridyl, indolinyl and fluorenyl, each of said aryl andheteroaromatic substituents in (e) (ii) and (iii) being selected fromthe group consisting of hydroxy, aryl, mono(C₁-C₆)alkoxyaryl,di(C₁-C₆)alkoxyaryl, mono(C₁-C₆)alkylaryl, di(C₁-C₆)alkylaryl,chloroaryl, fluoroaryl, C₃-C₇ cycloalkylaryl, C₃-C₇ cycloalkyl, C₃-C₇cycloalkyloxy, C₃-C₇ cycloalkyloxy(C₁-C₆)alkyl, C₃-C₇cycloalkyloxy(C₁-C₆)alkoxy, aryl(C₁-C₆)alkyl, aryl(C₁-C₆)alkoxy,aryloxy, aryloxy(C₁-C₆)alkyl, aryloxy(C₁-C₆)alkoxy, mono- anddi-(C₁-C₆)alkylaryl(C₁-C₆)alkyl, mono- anddi-(C₁-C₆)alkoxyaryl(C₁-C₆)alkyl, mono- anddi-(C₁-C₆)alkylaryl(C₁-C₆)alkoxy, mono- anddi-(C₁-C₆)alkoxyaryl(C₁-C₆)alkoxy, amino, mono(C₁-C₆)alkylamino,di(C₁-C₆)alkylamino, diarylamino, piperazino, N-(C₁-C₆)alkylpiperazino,N-arylpiperazino, aziridino, indolino, piperidino, morpholino,thiomorpholino, tetrahydroquinolino, tetrahydroisoquinolino, pyrrolidyl,C₁-C₆ alkyl, C₁-C₆ chloroalkyl, C₁-C₆ fluoroalkyl, C₁-C₆ alkoxy,mono(C₁-C₆)alkoxy(C₁-C₄)alkyl, acryloxy, methacryloxy, bromo, chloro andfluoro, said aryl being phenyl or naphthyl; (iv) the unsubstituted ormono-substituted groups pyrazolyl, imidazolyl, pyrazolinyl,imidazolinyl, pyrrolinyl, phenothiazinyl, phenoxazinyl, phenazinyl oracridinyl, each of said substituents being selected from the groupconsisting of C₁-C₆ alkyl, C₁-C₆ alkoxy, phenyl, fluoro, chloro andbromo; (v) monosubstituted phenyl, having a substituent at the paraposition that is a linking group, —(CH₂)_(t)— or —O—(CH₂)_(t)—, whereint is the integer 1, 2, 3, 4, 5 or 6, connected to an aryl group, whichis a member of another photochromic naphthopyran; (vi) the groupsrepresented by the following graphic formulae:

 wherein A is methylene or oxygen and D is oxygen or substitutednitrogen, provided that when D is substituted nitrogen, A is methylene,said nitrogen substituents being selected from the group consisting ofhydrogen, C₁-C₆ alkyl, and C₂-C₆ acyl; each R₂₄ is C₁-C₆ alkyl, C₁-C₆alkoxy, hydroxy, chloro or fluoro; R₂₂ and R₂₃ are each hydrogen orC₁-C₆ alkyl; and q is the integer 0, 1, or 2; (vii) C₁-C₆ alkyl, C₁-C₆chloroalkyl, C₁-C₆ fluoroalkyl, C₁-C₆ alkoxy(C₁-C₄)alkyl, C₃-C₆cycloalkyl, mono(C₁-C₆)alkoxy(C₃-C₆)cycloalkyl, mono(C₁-C₆)alkyl(C₃-C₆)cycloalkyl, chloro(C₃-C₆)cycloalkyl, fluoro(C₃-C₆)cyclo-alkyl and C₄-C₁₂bicycloalkyl; and (viii)the group represented by the following graphicformula:

 wherein L is hydrogen or C₁-C₄ alkyl and M is selected from theunsubstituted, mono-, and di-substituted members of the group consistingof naphthyl, phenyl, furanyl, and thienyl, each of said groupsubstituents being C₁-C₄ alkyl, C₁-C₄ alkoxy, fluoro, or chloro; or (f)B and B′ taken together form fluoren-9-ylidene, mono-, or di-substitutedfluoren-9-ylidene or a member selected from the group consisting ofsaturated C₃-C₁₂ spiro-monocyclic hydrocarbon rings, saturated C₇-C₁₂spiro-bicyclic hydrocarbon rings, and saturated C₇-C₁₂ spiro-tricyclichydrocarbon rings, each of said fluoren-9-ylidene substituents beingselected from the group consisting of C₁-C₄ alkyl, C₁-C₄ alkoxy, fluoroand chloro.
 3. The naphthopyran of claim 2 wherein, (a) R₁ and R₂ areeach selected from the group consisting of hydrogen, hydroxy, C₁-C₄alkyl, C₃-C₆ cycloalkyl, chloro, fluoro and the group, —OR₈, wherein R₈is C₁-C₃ alkyl, phenyl(C₁-C₂)alkyl, mono(C₁-C₃)alkyl substitutedphenyl(C₁-C₃)alkyl, mono(C₁-C₃)alkoxy substituted phenyl(C₁-C₃)alkyl,C₁-C₃ alkoxy(C₂-C₄)alkyl, C₁-C₃ chloroalkyl, C₁-C₃ fluoroalkyl, thegroup, —CH(R₉)Q, wherein R₉ is hydrogen or C₁-C₂ alkyl and Q is —CN or—COOR₁₀, and R₁₀ is hydrogen or C₁-C₂ alkyl, or R₈ is the group, —C(O)V,wherein V is hydrogen, C₁-C₃ alkyl, C₁-C₃ alkoxy, phenyl, naphthyl, themono-substituted aryl groups, phenyl or naphthyl, phenoxy, mono- ordi-(C₁-C₃)alkyl substituted phenoxy, mono- or di-(C₁-C₃)alkoxysubstituted phenoxy, mono(C₁-C₃)alkylamino, phenylamino, mono- ordi-(C₁-C₃)alkyl substituted phenylamino, or mono- or di-(C₁-C₃)alkoxysubstituted phenylamino, and said aryl substituents being C₁-C₃ alkyl orC₁-C₃ alkoxy, or R₁ and R₂ are each the group T, x and y are each anumber between 0 and 50, z is 0 and the sum of x and y is between 2 and50; (b) R₃ is C₁-C₆ alkyl, C₁-C₆ alkoxy, chloro or fluoro; (c) R₄ isselected from hydrogen, C₁-C₃ alkyl, chloro or fluoro; or R₄, R₅ and R₆are each selected from the group consisting of (i) the group, —OR₈′,wherein R₈′ is —CH(R₉)Q and Q is —CN; and (ii) a group selected from:(1) —N(R₁₅)R₁₆, wherein R₁₅ and R₁₆ are C₁-C₄ alkyl; (2) a nitrogencontaining ring represented by the graphic formula:

 wherein Y is —CH₂— or —CH(R₁₇)—, X is —O—, —NH— or —NR₁₇— and R₁₇ isC₁-C₃ alkyl; (3) a group represented by the following graphic formulae:

 wherein R₁₉, R₂₀ and R₂₁ are each hydrogen or C₁-C₃ alkyl and R₁₈ isC₁-C₃ alkyl; or (iii) R₅ and R₆ together form the following graphicformulae:

 wherein J and K are oxygen; (d) R₇ is selected from hydrogen, C₁-C₃alkyl, chloro or fluoro; (e) B and B′ are each selected from the groupconsisting of: (i) phenyl, mono-substituted phenyl, and di-substitutedphenyl; (ii) the unsubstituted, mono-, and di-substituted aromaticheterocyclic groups furanyl, benzofuran-2-yl, thienyl, benzothien-2-yland dibenzofuranyl, said phenyl and aromatic heterocyclic substituentsin (e)(i) and (ii) being selected from the group consisting of hydroxy,amino, mono(C₁-C₃)alkyl-amino, di(C₁-C₃)alkylamino, piperidino,morpholino, pyrrolidyl, C₁-C₃ alkyl, C₁-C₃ chloroalkyl, C₁-C₃fluoroalkyl, C₁-C₃ alkoxy, mono(C₁-C₃)alkoxy (C₁-C₃)alkyl, fluoro andchloro; (iii) the groups represented by the following graphic formulae:

 wherein A is methylene and D is oxygen, R₂₄ is C₁-C₃ alkyl or C₁-C₃alkoxy, R₂₂ and R₂₃ are each hydrogen or C₁-C₄ alkyl; and q is theinteger 0 or 1; (iv) C₁-C₄ alkyl; and (v) the group represented by thefollowing graphic formula:

 herein L is hydrogen or methyl and M is phenyl or mono-substitutedphenyl, said phenyl substituent being selected from the group consistingof C₁-C₃ alkyl, C₁-C₃ alkoxy, and fluoro; or (f) B and B′ taken togetherform a fluoren-9-ylidene, mono-substituted fluoren-9-ylidene or a memberselected from the group consisting of saturated C₃-C₈ spiro-monocyclichydrocarbon rings, saturated C₇-C₁₀ spiro-bicyclic hydrocarbon rings,and saturated C₇-C₁₀ spiro-tricyclic hydrocarbon rings, saidfluoren-9-xylidene substituent being selected from the group consistingof C₁-C₃ alkyl, C₁-C₃ alkoxy, fluoro and chloro.
 4. The naphthopyrancompound of claim 3 wherein, (a) R₁ and R₂ are each hydrogen, C₁-C₃alkyl, the group, —OR₈, wherein R₈ is C₁-C₃ alkyl or, R₁ and R₂ are eachthe group T and x is a number between 2 and 50, y and z are each 0; (b)R₃ is C₁-C₃ alkoxy; (c) R₄ is hydrogen; or R₄, R₅ and R₆ are each C₁-C₃alkoxy; (d) R₇ is hydrogen; and (e) B and B′ are each selected from thegroup consisting of phenyl, mono-, and di-substituted phenyl,unsubstituted, mono-, and di-substituted aromatic heterocyclic groupsfuranyl, benzofuran-2-yl, thienyl, benzothien-2-yl, and dibenzofuranyleach of said phenyl and aromatic heterocyclic substituents beingselected from the group consisting of hydroxy, C₁-C₃ alkyl, C₁-C₃alkoxy, fluoro and chloro; and the group represented by the followinggraphic formula:

wherein A is methylene and D is oxygen, R₂₄ is C₁-C₃ alkyl or C₁-C₃alkoxy, R₂₂ and R₂₃ are each hydrogen or C₁-C₃ alkyl, and q is theinteger 0 or 1; or B and B′ taken together form fluoren-9-ylidene,adamantylidene, bornylidene, norbornylidene, orbicyclo(3.3.1)nonan-9-ylidene.
 5. A naphthopyran compound selected fromthe group consisting of: (a)3,3-di(4-methoxyphenyl)-6,7,10,11-tetramethoxy-13,13-dimethyl-3H,13H-indeno[2,1-f]naphtho[1,2-b]pyran;(b)3-phenyl-3-(4-morpholinophenyl)-6,7,10,11-tetramethoxy-13,13-dimethyl-3H,13H-indeno[2,1-f]naphtho[1,2-b]pyran;(c)3,3-di(4-methoxyphenyl)-6,7,10,11-tetramethoxy-13-hydroxy-13-ethyl-3H,13H-indeno[2,1-f]naphtho[1,2-b]pyran;(d)3,3-di(4-methoxyphenyl)-6,7-dimethoxy-13,13-dimethyl-3H,13H-indeno[2,1-f]naphtho[1,2-b]pyran;(e)3,3-di(4-methoxyphenyl)-6,7-dimethoxy-13-hydroxy-13-ethyl-3H,13H-indeno[2,1-f]naphtho[1,2-b]pyran;(f)3,3-di(4-methoxyphenyl)-6,7,10,11-tetramethoxy-13,13-diethyl-3H,13H-indeno[2,1-f]naphtho[1,2-b]pyran;(g)3,3-di(4-methoxyphenyl)-6,7-dimethoxy-13-phenyl-3H,13H-indeno[2,1-f]naphtho1,2-b]pyran;(h)3-(4-methoxyphenyl)-3-(4-morpholinophenyl)-6,7-dimethoxy-13-phenyl-3H,13H-indeno[2,1-f]naphtho[1,2-b]pyran;(i)3-(4-methoxyphenyl)-3-(4-morpholinophenyl)-6,7-dimethoxy-13,13-dimethyl-3H,13H-indeno[2,1-f]naphtho[1,2-b]pyran;(j)3-(4-methoxyphenyl)-3-(4-dimethylaminophenyl)-6,7-dimethoxy-13,13-dimethyl-3H,13H-indeno[2,1-f]naphtho[1,2-b]pyran;(k)3,3-di(4-methoxyphenyl)-6,7,8-trimethoxy-13-phenyl-3H,13H-indeno[2,1-f]naphtho[1,2-b]pyran;(l)3-(4-methoxyphenyl)-3-(4-morpholinophenyl)-6,7,10,11-tetramethoxy-13-hydroxy-13-ethyl-3H,13H-indeno[2,1-f]naphtho[1,2-b]pyran;(m)3-(4-methoxyphenyl)-3-(4-morpholinophenyl)-6,7,10,11-tetramethoxy-13-hydroxy-13-butyl-3H,13H-indeno[2,1-f]naphtho[1,2-b]pyran;(n)3-(4-morpholinophenyl)-3-phenyl-6,7-dimethoxy-13-hydroxy-13-ethyl-3H,13H-indeno[2,1,-f]naphtho[1,2-b]pyran;(o)3,3-di(4-methoxyphenyl)-6,7-dimethoxy-13-hydroxy-13-butyl-3H,13H-indeno[2,1,-f]naphtho[1,2-b]pyran;(p)3-(4-morpholinophenyl)-3-phenyl-6,7-dimethoxy-13-hydroxy-13-butyl-3H,13H-indeno[2,1,-f]naphtho[1,2-b]pyran;(q)3-(4-methoxyphenyl)-3-(4-morpholinophenyl)-6,7-dimethoxy-13-hydroxy-13-ethyl-3H,13H-indeno[2,1-f]naphtho[1,2-b]pyran;(r)3-(4-methoxyphenyl)-3-(4-morpholinophenyl)-6,7-dimethoxy-13-ethyl-13-methoxy-3H,13H-indeno[2,1-f]naphtho[1,2-b]pyran;(s) 3-(4-methoxyphenyl)-3-(4-morpholinophenyl)-56,7-dimethoxy-13-hydroxy-13-methyl-3H,13H-indeno[2,1-f]naphtho[1,2-b]pyran;and (t)3-(4-methoxyphenyl)-3-(4-morpholinophenyl)-6,7-dimethoxy-13-methoxy-13-methyl-3H,13H-indeno[2,1-f]naphtho[1,2-b]pyran.6. A photochromic article comprising a polymeric organic host materialand a photochromic amount of the naphthopyran compound of claim
 1. 7.The photochromic article of claim 6 wherein the polymeric organic hostmaterial is selected from the group consisting of poly(C₁-C₁₂ alkylmethacrylates), poly(oxyalkylene) dimethacrylates, poly(alkoxylatedphenol methacrylates), cellulose acetate, cellulose triacetate,cellulose acetate propionate, cellulose acetate butyrate, poly(vinylacetate), poly(vinyl alcohol), poly(vinyl chloride), poly(vinylidenechloride), thermoplastic polycarbonates, polyesters, polyurethanes,polythiourethanes, poly(ethylene terephthalate), polystyrene, poly(alphamethylstyrene), copoly(styrene-methylmethacrylate),copoly(styrene-acrylonitrile), polyvinylbutyral and polymers of membersof the group consisting of polyol(allyl carbonate) monomers,polyfunctional acrylate monomers, polyfunctional methacrylate monomers,diethylene glycol dimethacrylate monomers, diisopropenyl benzenemonomers, ethoxylated bisphenol A dimethacrylate monomers, ethyleneglycol bismethacrylate monomers, poly(ethylene glycol) bismethacrylatemonomers, ethoxylated phenol methacrylate monomers, alkoxylatedpolyhydric alcohol acrylate monomers and diallylidene pentaerythritolmonomers.
 8. The photochromic article of claim 7 wherein the polymericorganic host material is a solid transparent polymer selected from thegroup consisting of poly(methyl methacrylate), poly(ethylene glycol)bismethacrylate, poly(ethoxylated bisphenol A) dimethacrylate,thermoplastic polycarbonate, poly(vinyl acetate), polyvinylbutyral,polyurethane, polythiourethane and polymers of members of the groupconsisting of diethylene glycol bis(allyl carbonate) monomers,diethylene glycol dimethacrylate monomers, ethoxylated phenolmethacrylate monomers, diisopropenyl benzene monomers and ethoxylatedtrimethylol propane triacrylate monomers.
 9. The photochromic article ofclaim 8 wherein the photochromic compound is present in an amount offrom about 0.05 to 2.0 milligram per square centimeter of organic hostmaterial surface to which the photochromic substance(s) is incorporatedor applied.
 10. The photochromic article of claim 9 wherein the articleis a lens.
 11. A photochromic article comprising a polymeric organichost material selected from the group consisting of poly(methylmethacrylate), polylethylene glycol) bismethacrylate, poly(ethoxylatedbisphenol A) dimethacrylate, thermoplastic polycarbonate, poly(vinylacetate), polyvinylbutyral, polyurethane, polythiourethane and polymersof members of the group consisting of diethylene glycol bis(allylcarbonate) monomers, diethylene glycol dimethacrylate monomers,ethoxylated phenol methacrylate monomers, diisopropenyl benzene monomersand ethoxylated trimethylol propane triacrylate monomers and aphotochromic amount of the naphthopyran compound of claim
 2. 12. Aphotochromic article comprising a polymeric organic host materialselected from the group consisting of poly(methyl methacrylate),poly(ethylene glycol) bismethacrylate, poly(ethoxylated bisphenol A)dimethacrylate, thermoplastic polycarbonate, polylvinyl acetate),polyvinylbutyral, polyurethane and polymers of members of the groupconsisting of diethylene glycol bis(allyl carbonate) monomers,diethylene glycol dimethacrylate monomers, ethoxylated phenolmethacrylate monomers, diisopropenyl benzene monomers and ethoxylatedtrimethylol propane triacrylate monomers, and a photochromic amount ofthe naphthopyran compound of claim
 3. 13. A photochromic articlecomprising a polymerizate of an optical organic resin monomer and aphotochromic amount of the naphthopyran compound of claim
 1. 14. Thephotochromic article of claim 13 wherein the refractive index of thepolymerizate is from about 1.48 to about 1.75.
 15. The photochromicarticle of claim 13 wherein the polymerizate is an optical element. 16.The photochromic article of claim 15 wherein said optical element is anophthalmic lens or a contact lens.
 17. A photochromic articlecomprising, in combination, a solid transparent polymeric organic hostmaterial, and a photochromic amount of each of (a) at least onenaphthopyran compound of claim 1, and (b) at least one other organicphotochromic compound having at least one activated absorption maximawithin the range of between about 400 and 700 nanometers.
 18. Thephotochromic article of claim 17 wherein the polymeric organic hostmaterial is a solid transparent homopolymer or copolymer selected fromthe group consisting of poly(methyl methacrylate), poly(ethylene glycolbis methacrylate), poly(ethoxylated bisphenol A) dimethacrylate,thermoplastic polycarbonate, poly(vinyl acetate), polyvinylbutyral,polyurethane and polymers of members of the group consisting ofdiethylene glycol bis(allyl carbonate) monomers, diethylene glycoldimethacrylate monomers, ethoxylated phenol methacrylate monomers,diisopropenyl benzene monomers and ethoxylated trimethylol propanetriacrylate monomers.
 19. The photochromic article of claim 17 whereinthe organic photochromic compound (b) is selected from the groupconsisting of naphthopyrans, benzopyrans, phenanthropyrans,indenonaphthopyrans, oxazine, metal-dithiozonates, fulgides, fulgimides,spiro(indoline)pyrans, and mixtures of such photochromic compounds. 20.The photochromic article of claim 19 wherein the photochromic compoundis present in an amount of from about 0.05 to 2.0 milligram per squarecentimeter of organic host material surface to which the photochromicsubstance(s) is incorporated or applied.
 21. The photochromic article ofclaim 20 wherein the article is an ophthalmic lens or a contact lens.22. A photochromic article comprising, in combination, a polymericorganic host material selected from the group consisting of poly(methylmethacrylate), poly(ethylene glycol) bismethacrylate, poly(ethoxylatedbisphenol A) dimethacrylate, thermoplastic polycarbonate, poly(vinylacetate), polyvinylbutyral, polyurethane and polymers of members of thegroup consisting of diethylene glycol bis(allyl carbonate) monomers,diethylene glycol dimethacrylate monomers, ethoxylated phenolmethacrylate monomers, diisopropenyl benzene monomers and ethoxylatedtrimethylol propane triacrylate monomers, and a photochromic amount ofeach of (a) at least one naphthopyran compound of claim 2, and (b) atleast one other organic photochromic compound having at least oneactivated absorption maxima within the range of between about 400 and700 nanometers.
 23. A photochromic article comprising, in combination, apolymeric organic host material selected from the group consisting ofpoly(methyl methacrylate), poly ethylene glycol) bismethacrylate, polyethoxylated bisphenol A) dimethacrylate, thermoplastic polycarbonate,poly(vinyl acetate), polyvinylbutyral, polyurethane and polymers ofmembers of the group consisting of diethylene glycol bis(allylcarbonate) monomers, diethylene glycol dimethacrylate monomers,ethoxylated phenol methacrylate monomers, diisopropenyl benzene monomersand ethoxylated trimethylol propane triacrylate monomers, and aphotochromic amount of each of (a) at least one naphthopyran compound ofclaim 3, and (b) at least one other organic photochromic compound havingat least one activated absorption maxima within the range of betweenabout 400 and 700 nanometers.